instruction: Is the next sentence syntactically and semantically acceptable?

Peter was at the party

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

The person whom they intended to speak with agreed to reimburse us.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Absolutely an owl hunts mice.

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

I've never seen a man taller than my mother.

response:
acceptable