Help with 8th grade english

DIRECTIONS: Underline each object pronoun and HIGHLIGHT whether it is a direct object (DO), an indirect object (IO), or an object of a preposition (OP).

13.
The book about mechanics was written by him.
DO
IO
OP

14.
The coach and she purchased the tickets for the bus.
DO
IO
OP
15.
Mr. Talmadge mailed a check for her.
DO
IO
OP