Task: Question Answering
Input (English): Passage: Dad thought the yard looked empty and the sun was making the house too warm in the afternoon . He decided to go out and buy a tree . He got his truck out of the garage and asked his son to come along to help him pick out a nice tree .  They parked in the parking lot , and got out of the truck , and saw many trees . The da asked his son , which kind of tree do you think would be best ? His son said , a nice big tree that will help fill the yard and block the wall of our house from the sun .  The boy walked up and down the rows of trees and found one he liked . His dad asked the worker to load the tree into the truck and paid for the tree inside the store . The dad and his son drove out of the parking lot and went home feeling happy .  The boy 's dad said , " Now when we get home I can teach you how to plant a tree ! " Question: who was the dad the father to? Option1: The tree. Option2: his son
Output (English): his son