Answered

One of the following sentences contains an independent clause and a dependent clause, which makes it a
complex sentence. Which is the complex sentence?
A. I hesitated a moment, but her smile gave me courage.
B. After the rain ended, the sky became blue.
C. Jenny was the largest elephant in the circus.
D. I came home; I saw an envelope in the mailbox.



Answer :

It's B: After the rain ended, the sky became blue.
You can tell because a dependent clause cannot stand by itself to be a sentence. "After the rain ended" cannot be a sentence by itself.
All of the others can.

Hopefully this helps, if not i'd be happy to explain it more.

All the best,
17cruzc