So,
Normally a unit rate will be x per 1y. Example: 60 miles/1hr.
Therefore, the option with the denominator as 1 would be the unit rate.
The correct option is C.
So using whole number rounding I believe the answer you should get would be 141,550 as 3217 x 44 is equals to 141,548 so the answer may be 141,550 since 50 is the closest ten number to 48, with a distance of only 2 numbers.