Which statement about life on Earth is true? a) Dinosaurs appeared before insects. b) Dinosaurs and insects appeared at the same time. c) Humans have been on Earth for hundreds of millions of years. d) Humans have been on Earth for a very short amount of time.

The answer is D, Because dinosaurs appears in the Triassic period while insects appeared in the Devonian period which is about 160 million years about, which rules out A and B. Humans have been on Earth for almost 3 million years, which is nothing compared to the history of life in earth, which about 4,000 million years of life history, so D