A dog barks in a park and hears its echo after 0.5 seconds. The sound of its bark got reflected by a nearby building. The sound of speed in air is 346 m/s. The distance between the dog and the building is
A 86.5 m
B 80.6 m
C 75 m
D 8.65 m
'Sound of Speed' yes, I see nothing wrong here.