Please choose the correct answer to the question: An earthquake in the Earth's crust under the ocean releases sound waves. Which statement accurately describes how the sound waves spread?

Answer1: They spread in all directions away from their source. Answer2: They remain trapped near the source by water pressure. Answer3: They travel mostly horizontally along the ocean floor. Answer4: They travel mostly upward toward the surface of the water.

Answer format: answer1/answer2/answer3/answer4
Answer: answer1