A cheetah can run at approximately 30.0 m/s, and a gazelle at 20.0 m/s. If both animals are running at full speed, with the gazelle 50.0 m ahead, how long before the cheetah catches its prey?

A) 5.0 s
B) 10.0 s
C) 15.0 s
D) 20.0 s