Answer:
D. People per hour, because the dependent quantity is the people
Step-by-step explanation:
A unit rate is some quantity divided by one unit of another quantity. Often a "rate" is the measure of some quantity per period of time. Here, hours are the period of time, so the usual measure of rate would have hours in the denominator.
Often, too, an independent quantity is multiplied by some factor in order to obtain the value of a dependent quantity. In the case where the factor is "people per hour", multiplying by the independent quantity of hours would give the dependent number of people.
