My question was deleted because it was "incomplete", but I'll answer again.
Simple
This sentence is simple because it contains one singular idea. It may be incorrectly identified as compound because the subject is compound (Forest rangers and volunteers). This is an easy mistake.
Hope this helps!! Good luck, mate. :)
Answer:
She had volunteered at a summer camp for ill children
Explanation:
I took the quiz
Whoever is the answer . i just took this assessment and go it right:)