The correct choice is whose. So what is the difference between whose and who's? The word whose is the possessive form of the pronoun who.

Whose is a possessive pronoun that you should use when you're asking or telling whom something belongs to. Who's is a contraction made up of the words who and is or who. Who's and whose are easy to confuse. Who's means who is or who has. Whose shows possession (e. g. , never trust a doctor whose plants have died). Who's is a contraction of who is, as in who's there? And the friend who's calling, or of who has, as in who's got the time? and the friend who's helped before.

Whose shows possession (e. g. , never trust a doctor whose plants have died). Who's is a contraction of who is, as in who's there? And the friend who's calling, or of who has, as in who's got the time? and the friend who's helped before. Who's is a contraction of who is or who has. It is used in questions and in statements, as shown in the examples below. [who is] who's.

[who is] who's.