Answer:

The correct answer is option 'B' - Gopal.

Explanation:

In the given statement, "It's happened to him ~ He's gone mad," the pronoun 'him' refers to a specific person who has experienced something that has caused him to go mad. To determine who 'he' is in this context, we need to analyze the options provided.

Let's evaluate each option:

a) Emperor: There is no information given in the statement that suggests the person being referred to as 'he' is an emperor. Hence, option 'a' can be ruled out.

b) Gopal: The statement does not provide any background information about Gopal. However, the use of the pronoun 'him' suggests that the person being mentioned is someone familiar to the speaker. Therefore, option 'b' is a possible choice.

c) Gatekeeper: There is no mention of a gatekeeper in the statement, so option 'c' is unlikely.

d) A neighbor: The statement does not indicate any relationship with a neighbor or mention any neighbors. Therefore, option 'd' can be eliminated.

Based on the analysis above, the most suitable option is 'b' - Gopal. Although the statement does not provide specific details about Gopal or the events leading to his madness, we can infer that something has happened to him, causing him to lose his sanity.

Please note that this answer is based solely on the given information, and without further context, it is not possible to provide a more detailed explanation.