The answer is

In the choices; the coefficients 21, 32 and 10 are not perfect squares.
This is not an integer; an integer is a whole number that can be positive, negative, or zero such as -1, 0, and 1.
Answer:
.25 inches per hour
Step-by-step explanation:
.5 ft
-----------
day
We need to get to inches
1 ft = 12 inches
.5 ft 12 inches
----------- * ------------
day 1 ft
We also need to convert days to minutes
1 day = 24 hours
.5 ft 12 inches 1 day
----------- * ------------ * -------------
day 1 ft 24 hours
6 inches
-------------
24 hours
.25 inches per hour