Introducing a man, a woman said, 'His wife is the only daughter of my father.' How is that man related to the women ?

Husband

We have,

Introducing a man, a woman said, "His wife is the only daughter of my father."

Identify the woman's relationship with her father:

The woman says, "His wife is the only daughter of my father."

Therefore, "His wife" is the woman herself because she is the only daughter of her father.

Determine the man’s relationship to the woman:

Since the woman is "His wife," the man must be her husband.