Read the following passage about modern civilisation and energy carefully. Then answer the question that follows by choosing the best option. Passage summary: Modern civilisation depends heavily on energy from oil, coal, natural gas, nuclear, hydro, wind, solar power, and biomass. Oil powers most machines that move, but reserves of oil, gas, and coal are finite. As these fuels become scarce and expensive, the world will face an energy crisis. Humanity must therefore make a transition to sustainable energy sources, either in a planned way or in a forced, chaotic way. Question: What is the main theme of this passage?

Introduction / Context:
This reading comprehension question assesses your ability to identify the central theme of a passage, rather than focusing on isolated facts. The passage describes the heavy dependence of modern civilisation on various energy sources, explains that oil and other fossil fuels are finite, and warns that as these resources decline, a global energy crisis will arise. It then stresses the urgent need to move towards sustainable energy sources such as wind and solar power. The theme is therefore about the approaching energy crisis and the need to respond wisely.

Given Data / Assumptions:

• Modern civilisation depends on energy that must be abundant and economical.
• Around eighty five percent of world energy currently comes from fossil fuels like oil, coal, and natural gas.
• Oil is described as uniquely versatile but finite and approaching depletion within a limited number of years.
• Natural gas and coal are also finite and will eventually become scarce.
• As these resources become rare, they will become expensive, leading to a worldwide energy crisis.
• The passage calls for a planned transition to sustainable sources such as wind and solar power.

Concept / Approach:
To identify the theme, you must ask what overall message the author is trying to communicate. The passage is not simply listing energy resources. Instead, it builds an argument: current reliance on fossil fuels is unsustainable, depletion is approaching, costs will rise, and the world faces a serious crisis unless it shifts to sustainable energy. The mention of possible extinction of human beings highlights the seriousness of the crisis. Thus, the phrase that best captures this central concern is looming energy crisis.

Step-by-Step Solution:
Step 1: Skim the passage to see what it discusses most frequently: dependence on energy, finite fossil fuels, and future crisis. Step 2: Note the numerical estimates for how long oil, gas, and coal will last, which emphasise the limited nature of these resources. Step 3: Pay attention to sentences stating that scarcity will lead to high costs and a worldwide energy crisis. Step 4: Observe the warning that the transition to sustainable energy can be planned or forced and that the coming era of limited energy will be very difficult. Step 5: Compare each option with this overall message. Changing lives is too general and does not clearly express the crisis. Step 6: Energy resources describes a topic but does not capture the urgent warning about crisis. Step 7: Power in today world is vague and fails to express the focus on depletion and danger. Looming energy crisis accurately reflects the passage focus on an approaching global problem.

Verification / Alternative check:
Rephrase the passage in one sentence: Modern civilisation depends on finite fossil fuels that are running out, which will cause a severe energy crisis unless we shift to sustainable sources. This summary clearly matches the idea of a looming energy crisis. None of the other options captures both dependence and impending danger as clearly. Therefore, option b is the best summary of the theme.

Why Other Options Are Wrong:
Changing lives is too broad and does not reference energy at all. Energy resources is merely a neutral label and could describe a passage that only lists different sources without highlighting the crisis. Power in today world is also generic and does not focus on depletion, rising prices, and crisis. Only looming energy crisis communicates the sense of an approaching global problem that runs through the entire passage.

Common Pitfalls:
Students sometimes confuse the topic with the theme. The topic here is energy resources and modern civilisation, but the theme is the author perspective on that topic, namely that a major crisis is approaching. Another mistake is focusing on the first line of the passage and ignoring later warnings. Always read the whole passage and pay attention to any concluding remarks that reveal the author main message.

Final Answer:
The main theme of the passage is a looming energy crisis caused by the depletion of finite fossil fuels.