Option B is the correct answer because of the following reasons:

1. The question is specific to the UPSC category: The question clearly states that it belongs to the UPSC category. Therefore, the correct answer should be related to UPSC and not any other option.

2. Elimination of other options: Let's analyze the other options to understand why they are not correct answers.

a) - This option is not correct because it does not provide any information or explanation about the correct answer. It does not relate to the question or provide any relevant details.

c) - This option is not correct because it does not provide any information or explanation about the correct answer. It does not relate to the question or provide any relevant details.

d) - This option is not correct because it does not provide any information or explanation about the correct answer. It does not relate to the question or provide any relevant details.

3. The importance of providing a detailed answer: The question specifically asks for a detailed explanation of the correct answer. Option B is the only option that provides a detailed explanation, while the other options do not.

4. Following the rules and guidelines: The question also mentions certain rules and guidelines that need to be followed while answering. Option B is the only option that adheres to these rules by providing a detailed and informative response.

In conclusion, option B is the correct answer because it is the only option that relates to the UPSC category, provides a detailed explanation, and follows the given rules and guidelines.