A catastrophic earthquake is one with a magnitude over 9.0. It has strong effects over areas thousands of miles in diameter. Catastrophic earthquakes are recorded about once every

A catastrophic earthquake is one with a magnitude over 9.0. It has strong effects over areas thousands of miles in diameter. Catastrophic earthquakes are recorded about once every
A)month.
B)2 years.
C)20 years.
D)500 years.