How is the underlined pronoun used in the sentence?

we're trying to find out(( whose ))car is parked in front of our driveway.

a.
object of a preposition

b.
direct object

c.
possessive

d.
subject

Which statement best explains the function of the subtitlein this text? a. it provides additional information that narrows the focusof the text. b.it draws attention to important information in the table ofcontents. c.it introduces the various sections that appear withineach chapter. d.it explains the author's primary reason for writing aboutthis topic. correct (a)