Answer:
a. Variable cost
Explanation:
Variable cost -
It refers to the amount of money which increases or decreases with the production output , is referred to as variable cost .
Variable cost is directly proportional to the production .
For example , the cost of raw material increases as the production of the output increases .
In numerical terms , the variable cost is the sum of the marginal cost over the total units .
The summation of the fixed cost and variable cost gives the total cost .
Hence , from the given scenario of the question ,
The correct option is a. Variable cost .