Choose the grammatically correct sentence: A) Whos book is this? B) Whose book is this? C) Who's book is this? D) Whose's book is this?

Choose the grammatically correct sentence: A) Whos book is this? B) Whose book is this? C) Who's book is this? D) Whose's book is this?

Explanation

"Whose" shows possession.

"Who's" means "who is," which doesn't fit here.