on If the highest level of activity achieved in a period in a company is 80,000 units with the total cost of $ 60,000 and the lowest level of activity achieved in that period is 40,000 unit with a total cost of $ 36,000, what is the total variable cost at the highest level of activity? O a. $ 52,000 O b. $40,000 O c. $ 48,000 O d. $ 42,000