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

How can behavioral science be applied in improving public health? a.by tracking a disease to determine its sourceb.by creating promotions that improve health habitscboth by tracking a disease to determine its source and by creating promotions that improve health habitsd.neither by tracking a disease to determine its source or by creating promotions that improve health habits