Which sentence is a simple sentence?

A.
I enjoy camping outdoors, but I prefer to have my own tent.

B.
When the lightning hit the tree, a branch came crashing down.

C.
His favorite ice cream is peppermint; mine is strawberry.

D.
During the flight, I took pictures of the clouds.

Question

Which sentence is a simple sentence?	
 
 A.
I enjoy camping outdoors, but I prefer to have my own tent.
 
 B.
When the lightning hit the tree, a branch came crashing down.
 
 C.
His favorite ice cream is peppermint; mine is strawberry.
 
 D.
During the flight, I took pictures of the clouds.

lovelyanna · Answer

I think D. The rest aren't simple sentences.