Marcus came across this excerpt in a book about Japanese history: In 1274 and 1281, the Mongols attempted to conquer Japan, but, in both cases, the invasions were unsuccessful because of massive typhoons. These severe weather events destroyed most of the invading ships or forced them to return home.

What is the relationship between the two sentences in this excerpt?
A. The first sentence describes a cause, and the second sentence describes the effect.
B. The first sentence describes events, and the second sentence compares those events to others.
C. The first sentence presents a problem, and the second sentence offers a solution to that problem.
D. The first sentence explains the first step in a sequence, and the second sentence explains the second step.