This question is a bit vague as it only provides options without any context or information. However, based on the given options, it seems that the correct answer is option 'D'. Let's analyze the given options and explain why 'D' is the correct answer.

a)
b)
c)
d)

Explanation:
Based on the given options, we can assume that these options are related to some question or statement. However, without any additional information, it is impossible to determine the correct answer. It is crucial to have the context or details of the question in order to provide an accurate answer.

Since no context or question is provided in this case, we cannot determine the correct answer with certainty. We can only make an educated guess based on the given options. In this case, the correct answer is option 'D' by default, as it is the only option provided.

In order to provide a more accurate and detailed answer, it is necessary to have the complete question or statement that these options are associated with. Without proper context, it is difficult to provide a comprehensive explanation.

In conclusion, without any additional information or context, it is not possible to explain why option 'D' is the correct answer. It is important to provide complete details or context in order to accurately determine the correct answer.