Based on the given passage about ants, choose the option that best explains why ants are described as Earth's most successful species.

Introduction / Context:
This is a reading comprehension question based on a passage that describes ants, their history, and their characteristics. The passage states that ants have been living on earth for more than one hundred million years and that they can be found almost anywhere on the planet. These two facts combine to support the statement that ants are Earth's most successful species. To answer correctly, you must recall these details and select the option that includes both reasons.

Given Data / Assumptions:

The passage explains that ants have lived on earth for more than one hundred million years.

It also states that they can be found almost anywhere on the planet.

The passage mentions that there are about twenty thousand different species of ants.

The phrase Earth's most successful species is used in the passage.

We must choose the option that reflects the reason given in the passage, not our own guess.

Concept / Approach:

Reading comprehension questions often test your ability to connect statements explicitly made in the passage. Here, the key is to identify which facts are directly linked with the claim that ants are the most successful species. The passage explicitly connects their long survival time and their widespread distribution to this label. Therefore, the correct answer will combine those two features: great age on earth and presence in almost all locations. Options that mention only one reason or that give incorrect numbers must be rejected as partial or wrong.

Step-by-Step Solution:
Step 1: Recall the sentence from the passage that explains why ants have been called Earth's most successful species. Step 2: Note that the passage first states their age on earth (more than one hundred million years) and their almost universal presence on the planet. Step 3: Examine option a: Because they have been on earth for more than a hundred million years. This includes only one part of the reason, their age. Step 4: Examine option b: Because they can be found almost anywhere on earth. This includes only their distribution, missing the time factor. Step 5: Examine option c: Because they have been on earth for more than a hundred million years and because they can be found almost anywhere on earth. This combines both key points and matches the explanation in the passage. Step 6: Examine option d: Because there are two thousand different species of ants on earth. The passage mentions about twenty thousand species, so this number is wrong. Step 7: Examine option e: Because they are larger than most other insects. This is not stated in the passage and is false. Step 8: Conclude that option c correctly summarises the reasons given in the passage.

Verification / Alternative check:

If you go back to the passage and reread the lines around the phrase Earth's most successful species, you will see that the writer gives the long period of existence and the wide geographical spread immediately before or after that claim. No other reason is directly linked with the phrase. This cross check confirms that option c uses exactly those two features, therefore it matches the passage.

Why Other Options Are Wrong:

Option a is incomplete because it mentions only the time factor and ignores the distribution.

Option b is also incomplete because it mentions only the distribution and ignores the time factor.

Option d gives the wrong number of species and does not match the passage.

Option e introduces a new idea about size which is not stated at all.

Common Pitfalls:

Many students select answers that are partially true or that sound impressive without checking whether all parts of the option are supported by the passage. In such questions, paying attention to the words because and for this reason in the passage can help you locate the exact sentence that explains the claim. It is important not to add your own extra knowledge about ants, and instead to base your answer only on the information given.

Final Answer:

According to the passage, ants are called Earth's most successful species because they have been on earth for more than a hundred million years and because they can be found almost anywhere on earth.