Answer:
B: 57 mph=57 mph
Step-by-step explanation:
A steady pace means constant speed that it does not change over a period of time and direction of motion. A simple formula, for this case (constant speed)
where x is distance and t time. The subtract is final value minus initial value
We have the distance and time, then
C
x-4 is zero when x=4
so the one that contains the factor (x-4)
The detailed step by step calculation is as shown in the attached file