The correct answer is "They modify Earth’s surface." Earthquakes and tsunamis both have the ability to cause significant changes to the Earth's surface. However, it's important to note that while tsunamis can be triggered by earthquakes, they can also be caused by other factors such as volcanic eruptions or underwater landslides. Therefore, the statement "They only occur in the ocean" is incorrect. Additionally, earthquakes can occur both on landmasses and in the ocean, making the statement "They only occur on landmasses" incorrect as well. To understand the commonalities between earthquakes and tsunamis, it is helpful to research the causes, effects, and characteristics of each natural phenomenon.