Which of the following sentences contains an incorrect

pronoun shift? (1 point)
Avery and Jerry brought their dad a
slice of cake from dinner.
I thought I saw a dog bury their bone
under the tree.
Joe's grandfather broke his favorite
plate in the dishwasher.
Betsy was so excited to get her car
back from the mechanic.

I thought I saw a dog bury their bone

under the tree.