The active sections that are located along fault lines are called
a. seismic gaps.
b. seismic risks.
c. stress accumulations.
d. recurrence gaps

B. seismic risks.

The active sections that are located along fault lines are called seismic risks.
NOT:

A. seismic gaps. 
C. stress accumulations. 
D. recurrence gaps

If its history of, then b) because a) implies only present day (now)

Since the pully is a simple machine so the mechanical advantage is a 1