Velma Passes Mort at a Speed of 0

Multiple Choice

Velma passes Mort at a speed of 0.75c. At this speed, the "time dilation factor" is 1.5. In other words, Mort observes a 1- second tick of Velma's clock to take 1.5 seconds. Suppose that they are born at the same time, and that Velma observes herself to live 30 years. According to Mort's observations, how old is he when Velma dies?

A) 30 years
B) 45 years
C) 20 years
D) 10 years
E) 40 years