How Does the Accounting Rate of Return Differ from the Return

How does the accounting rate of return differ from the return on investment formula?

A) They are not different;both are calculated by dividing net operating income by initial investment.
B) The numerator in each formula differs;accounting rate of return divides net operating income by initial investment,and return on investment divides gross operating income by initial investment.
C) The numerator in each formula differs;accounting rate of return divides net operating income by average invested assets,while return on investment divides gross operating income by average invested assets.
D) The denominator in each formula differs;accounting rate of return divides net operating income by initial investment,while return on investment divides net operating income by average invested assets.