Horsepower is defined as work per unit of
a. work.
b. force.
c. torque.
d. time.

D ) time

Explanation:

Horsepower (hp) is a unit of measurement of power, in the foot-pound-second ( fps ) or English system which is used to express the rate at which mechanical energy is expendedThis also can be used as the rate at which work is done.horsepower is rarely used to express power in any form other than mechanical. power is the rate of workdone

Power is mainly measured in Watts (W) which is the SI unit of itTo convert from horsepower to kilowatts

                   1 hp = 0.746 kW