1/3 of an hour is 20 minutes so 20 divided by 4 is 5 minutes per 1 mile.
1/3 of a mile is 4 hours so a full mile would be 3 times 4 which is 12 so every 12 hours is 1 mile.
1/2 a mile takes 3 hours and 2 times 3 is 6 so every 6 hours is 1 mile.
A. 5 minutes per mile
B. 12 hours per mile
C. 6 hours per mile
The correct choice is A.
I hope this helped you