Prof. Amartya Sen has earned worldwide distinction and a Nobel Prize in which of the following academic fields?

Introduction / Context:
Prof. Amartya Sen is one of the most prominent Indian academics on the global stage. He is noted for research on welfare, poverty, development and democracy. Many competitive exams include questions on his field of work and the award he received from the Nobel committee. This question checks whether candidates can correctly identify his discipline from among several scientific fields.

Given Data / Assumptions:
- The question asks about the academic field of Prof. Amartya Sen.
- The options include economics, geology, biochemistry and astrophysics.
- The learner is expected to know that he is a Nobel laureate and public intellectual on development issues.
- We assume familiarity with at least one of his books or topics such as welfare economics and human development index ideas.

Concept / Approach:
The correct concept is to associate Amartya Sen with economics, in particular welfare and development economics. His work on famines, social choice, capabilities and freedoms is highly influential. None of the other fields listed match the topics he is known for. Geology studies earth, biochemistry deals with chemical processes in living organisms and astrophysics focuses on the universe, none of which are his main area.

Step-by-Step Solution:
Step 1: Recall that Prof. Amartya Sen is widely described as an economist in news reports and biographies. Step 2: Remember that he received the Nobel Prize for contributions to welfare economics and social choice theory. Step 3: Compare this with the nature of geology, biochemistry and astrophysics and see that these do not relate to poverty, inequality or democracy studies. Step 4: Conclude that the only field that fits his work is economics. Step 5: Mark "Economics" as the correct answer and reject the other options.

Verification / Alternative check:
A simple verification is to think of titles of his books such as works on famine, freedom and justice, which are clearly economic and philosophical in nature. Academic positions he has held at universities like Harvard, Oxford and Cambridge have been in economics and related social science departments. This pattern confirms that he is not a geologist, biochemist or astrophysicist. Therefore economics is the only accurate option.

Why Other Options Are Wrong:
Geology concerns the physical structure of Earth and processes such as plate tectonics and mineral formation, topics not related to Sen's known research.
Biochemistry deals with molecules and chemical reactions in living cells, very different from social and economic analysis.
Astrophysics focuses on stars, galaxies and cosmic phenomena; again, there is no connection with Sen's famous contributions.
For exam purposes, he is always presented as an economist and moral philosopher.

Common Pitfalls:
This question is straightforward, but careless candidates may misread the name or confuse him with other scientists. Another minor pitfall is overthinking and wondering if he had training in some other science, even though all GK references clearly call him an economist. To avoid such errors, focus on how a person is consistently described in textbooks and news articles rather than trying to guess hidden details.

Final Answer:
Economics