Bats sense objects in the dark by echolocation, emitting very short pulses of sound and then listening for their echoes off objects. A bat is flying directly toward a wall 170 m away when it emits a pulse. 0.95 s later, it receives the pulse. Let the speed of sound be
340

m/s
340m/s. What is the bat's speed?

a) 79.2 m/s
b) 85.4 m/s
c) 94.4 m/s
d) 101.1 m/s