Which of the following oil fields is recognised as the oldest oil field in India?

Introduction / Context:
Petroleum resources have played a major role in India economic development. Some oil fields are very old and have historical importance because they were among the first in Asia where oil was discovered and extracted. This question asks which oil field is considered the oldest oil field in India, a standard fact in Indian geography.

Given Data / Assumptions:
• Four options are given, including Mumbai High, Ankleshwar and Digboi, with one option labelled as none of the above. • The question refers specifically to the oldest oil field, not the largest or most productive. • We assume conventional historical knowledge of oil exploration in India. • Location and age of each field are relevant to the answer.

Concept / Approach:
Digboi in Assam is widely known as one of the oldest oil fields in India and is often referred to as the place where oil was discovered in the late nineteenth century by the British. Mumbai High is a large offshore field discovered much later in the twentieth century. Ankleshwar in Gujarat is also a significant onshore oil field, but it is younger than Digboi. Therefore, Digboi is the correct answer for the title of oldest oil field in India.

Step-by-Step Solution:
Step 1: Recall that Digboi in Assam was the site of early oil exploration under colonial administration in the late eighteen hundreds. Step 2: Recognise that Digboi oil field has been in operation for more than a century and is often called a historic field. Step 3: Compare this with Mumbai High, an offshore field discovered in the nineteen seventies, which makes it much newer. Step 4: Ankleshwar in Gujarat, though important, was also developed later than Digboi. Step 5: Therefore, the oldest oil field among the options is Digboi in Assam, making option C correct.

Verification / Alternative check:
Standard Indian geography books and multiple choice question banks mention Digboi as the oldest oil field in India and one of the earliest oil producing sites in Asia. Many exam explanations highlight that the phrase Dig boy, dig is linked to the story of discovering oil there, reinforcing its historical significance. No similar stories of being the oldest are associated with Mumbai High or Ankleshwar.

Why Other Options Are Wrong:
Option A: Mumbai High is the largest offshore oil field in India but was discovered in the twentieth century and is not the oldest. Option B: Ankleshwar in Gujarat is an important field but began production later than Digboi and therefore cannot be called the oldest. Option D: None of the above is incorrect because Digboi clearly fits the description of the oldest oil field in India.

Common Pitfalls:
Students sometimes pick Mumbai High because it is frequently mentioned in the context of oil production volumes and may assume popularity equals age. Others choose none of the above when they are unsure, even though Digboi is a classic fact. It is useful to separate facts about size or output from facts about historical first discoveries.

Final Answer:
The oldest oil field in India is Digboi in Assam.