Help me with this problem? GIVING BRAINLIEST!!

Answer:
Speed = Distance/time in km/h
a) 18 feet in 20 minutes
0.0054864 km/0.333333hours
=0.01645921645 km/h
b) 90 feet in 2.5 hours
0.027432km/2.5
=0.0109728 km/h
c) 20 yards in 1.5 hours
0.018288km/1.5
=0.012192 km/h
d) 3 2/3 yards in 15 minutes
0.003352800000003048km/0.25hours
=0.0134112
So I think its safe to say that A is the fastest in comparison