The correct option is Uncle.

To solve this blood relation puzzle, let us break down the statement made by the man step-by-step from his perspective:

1. "My father’s wife": The man's father's wife is the man's mother.

2. "My father’s wife’s only son": The only son of his mother (assuming the speaker is male, which is stated as "A man said...") is himself (the man).

3. "is the brother of your mother": Putting it together, "himself" is the brother of "your mother".

So, the man is your mother's brother.

Your mother's brother is your Uncle (maternal uncle).

Therefore, the man is related to you as your Uncle.