Which situation is the clearest example of cause and effect in "The City Without Us"?
A. Central Park has a garden that houses plants mentioned in
Shakespeare's plays.
B. Unheated buildings would result in a destructive freeze-thaw cycle.
C. While suspension bridges will last a few centuries, truss bridges
may last 1,000 years.
XO D. Water in Manhattan's underground spaces has to be pumped out
daily.