Answer:
C) If floodingwere to go unchecked, steel support beams in buildings would rust.
Step-by-step explanation:
The letter C, among all the options given in the question, gives a clear example of using the "cause and effect" system. Cause and effect refers to a situation where an event occurs, or may occur as a result of another event, which has occurred or may occur. In the case of the phrase in letter C, we can see that "if floods are not controlled" they will cause rust on steel beams in buildings; With this phrase we can realize that "flooding" is the cause and "steel beam rust in buildings" is the effect.