This question belongs to the UPPSC (UP) category and the correct answer is option 'A'. Let's analyze why option 'A' is the correct answer in detail.

Understanding the question
The question asks for the correct option among options 'a', 'b', 'c', and 'd'. We need to determine which option is correct and explain why.

Analyzing the options
To determine the correct answer, let's analyze each option one by one:

Option 'a':
Option 'b':
Option 'c':
Option 'd':

Explanation of the correct answer (option 'A')
Among the given options, option 'A' is the correct answer. To understand why, we need to analyze the context of the question and the information provided.

Unfortunately, the question does not provide any context, specific information, or any further details. Therefore, it is not possible to provide a detailed explanation of why option 'A' is the correct answer.

In order to provide a more accurate and informative response, it would be helpful to have additional information or context related to the question. Without any specific details or context, it is not possible to determine the correct answer or provide a comprehensive explanation.

Conclusion
In conclusion, the correct answer to this question cannot be determined without additional information or context. Option 'A' is marked as the correct answer, but without any specific details or context, it is not possible to explain why it is correct. It is important to have complete information and context in order to accurately answer a question.