Question

Which is a complete sentence?   A.

Started his homework late Sunday night.   B. Two energetic women walking in the park.   C. She did not understand what happened.   D. The exciting end of the baseball game.

Answer 1

"She did not understand what happened."

It is a complete sentence since it has a subject (she) and a verb (understand), and is independent (i.e. doesn't require another clause to make sense