Write a question about the following article.

The kids and I went to a farm and we decided to go for a walk along a trail . We walked through a corn field , a pumpkin field , from a distance we could see the apple orchard . It was beautiful .

Question:
What kind of vehicles might they NOT see ?
OPT:
a). Harvester.
b). Tractors.
c). Annihilator.
d). None of the above choices ..