Answer:
b) $20
Step-by-step explanation:
The minimum acceptable price per unit is $20.
This is because the minimum acceptable price is the break even price for the division. We will not include $7 fixed cost because it is not relevant to this transaction as it has to be paid regardless of this transfer.
The Minimum price thus is the price that cancels out all relevant costs namely the variable costs of $20.
Relevant costs are also known as the incremental costs that are incurred only when a particular activity is undertaken. Fixed costs as such are not incremental. Since there is spare capacity we are not forgoing any profits from external exchanges that needs to be accounted for.
Hope this helps