What causes a tsunami?

A tsunami is primarily caused by a series of ocean waves generated by large-scale disturbances, such as underwater earthquakes, volcanic eruptions, or landslides. When these geological events occur, they displace a significant volume of water, creating waves that travel at high speeds across the ocean. As these waves approach shallower coastal areas, their speed decreases, but their height increases dramatically, leading to the devastating impact that tsunamis are known for.

The other options do not accurately describe the cause of tsunamis. For instance, strong winds can lead to regular ocean waves, but they do not create tsunamis. The gravitational pull of the moon is responsible for tides, which are different phenomena, and changes in ocean temperature primarily affect ocean currents and weather patterns, not tsunami formation. Thus, option B correctly identifies the cause of tsunamis, focusing on the significant disturbances that displace water on a large scale.