To find the right answer, we have to remember that

The variable cost is that which changes, in our case, the variable cost is the price of each jersey. since each cost $23 and it increases as the number of jerseys increases.
Thus, the variable cost will be

The fixed cost is always constant. The fixed cost is the one-time set-up fee of 250.
Thus, we can combine the two costs to get the total cost.
The answer will be:
