The Lifetime of a Π⁺ Meson Normally Is 18 Nanoseconds

Multiple Choice

The lifetime of a Π⁺ meson normally is 18 nanoseconds.In a large particle accelerator,scientists can create p+ mesons moving at speeds very close to the speed of light.What do the scientists observe when they measure the lifetime of a Π⁺ meson that is created at very high speed?

A) The Π⁺ meson lasts 18 nanoseconds.
B) The Π⁺ meson lasts much less than 18 nanoseconds.
C) The Π⁺ meson lasts much more than 18 nanoseconds.
D) The Π⁺ meson no longer decays,and remains as a stable particle.