Answer:
B. $35
Step-by-step explanation:
While making these kind of decisions relevant cost is to be considered.
Since there is an idle capacity lying to meet the demand of Division B, the fixed cost shall be avoided while making this decision.
Thus, concerned cost is variable cost. Since the company is supplying in its own company to other division there might be some avoidable cost in the nature of variable, as for example: transportation, selling and marketing.
Here it is $5
Thus, relevant variable cost = $40 - $5 = $35
This represents the correct option.