Marginal Cost Equals Which of the Following

Multiple Choice

Marginal cost equals which of the following?
(i) the average fixed cost of the current unit
(ii) the change in total costs divided by change in quantity produced
(iii) the change in variable costs divided by change in quantity produced

A) (i) and (ii)
B) (ii) and (iii)
C) (ii) only
D) (i) , (ii) and (iii)