Answer:
B) Only statements II and III are correct.
Explanation:
The cost of understocking is the amount of money lost for each our of stock product = selling price - unit cost = $4 - $2 = $2
The optimal in-stock probability = cost of understocking / (cost of overstocking + cost of understocking) = $2 / ($1 + $2) = $2 / $3 = 0.667 = 67%