A Fast-Moving Muon Decays in 2 *10 ^{- 4} Seconds

Multiple Choice

A fast-moving muon decays in 2 *10 ^{- 4} seconds, as measured by an observer at rest.In the reference frame of the muon itself, its lifetime is in fact only 2 *10 ^{- 6} seconds.What is the muon's speed?

A) 0.05c
B) 0.50c
C) 0.95c
D) 0.995c
E) 0.99995c