The Top Cross Section Below Shows Earthquakes Along the San

The top cross section below shows earthquakes along the San Andreas fault before October 17, 1989 and the one on the bottom shows earthquakes along the same fault after that date. These two cross sections illustrate that:

A) one way to predict the locations of future earthquakes is to identify seismic gaps
B) San Francisco is due for an earthquake
C) the most dangerous part of a fault may be one that has not had recent earthquakes
D) all of these