Please choose the correct answer to the question: A scientist discovered a fossil of an ocean plant in the rocks of a desert. What does the discovery of this fossil most likely tell the scientist?

Answer1: The fossils were formed at the top of a mountain. Answer2: The fossils were formed during a rainstorm. Answer3: The area had many volcanic eruptions. Answer4: The area was once covered by water.

Answer format: answer1/answer2/answer3/answer4