Statement I is true. A tsunami is indeed a series of water waves that are caused by the displacement of a large volume of water in the ocean. This displacement can be caused by a variety of events such as earthquakes, volcanic eruptions, or underwater landslides.

Statement II is also true. A tsunami can be generated when thrust faults associated with convergent or destructive plate boundaries move abruptly. When these faults move, they can cause a sudden displacement of the ocean floor, which then sets off a series of waves that propagate through the water.

Option 1 is the correct answer because both statements are individually true and Statement II provides the correct explanation of Statement I. The displacement of water caused by the movement of thrust faults is what leads to the formation of tsunamis. Therefore, Statement II is indeed the correct explanation for Statement I.

No alert is necessary as the provided answer is correct.