The correct answer to this question is option 'B'. To understand why option 'B' is the correct answer, let's break down the question and the options provided.

Question:
?a)
b)
c)
d)

Explanation:
The question does not provide any context or specific information, so we need to rely solely on the given options to determine the correct answer.

Option 'A':
There is no information provided for option 'A', so we cannot consider it as the correct answer.

Option 'B':
Option 'B' is identified as the correct answer. However, without any context or further explanation, it is difficult to understand why this option is correct.

Option 'C':
There is no information provided for option 'C', so we cannot consider it as the correct answer.

Option 'D':
There is no information provided for option 'D', so we cannot consider it as the correct answer.

Conclusion:
Option 'B' is identified as the correct answer, but without any additional information, it is challenging to explain why this option is correct. To provide a more accurate and detailed explanation, it would be helpful to have more context or information related to the question.