annika company uses activity-based costing. the company has two products: a and b. the annual production and sales of product a is 4,000 units and of product b is 1,000 units. there are three activity cost pools, with total cost and activity as follows: total activity activity cost pool total cost product a product b total activity 1 $ 18,000 700 300 1,000 activity 2 $ 24,000 500 100 600 activity 3 $ 60,000 800 400 1,200 the activity-based costing cost per unit of product a is closest to: group of answer choices $17.00 $18.15 $20.40 $10.00