A Manufacturer Can Produce Radios at a Cost of $10 $200 e ^ { - 0.2 x }$

Multiple Choice

A manufacturer can produce radios at a cost of $10 apiece and estimates that if they are sold for x dollars apiece, consumers will buy approximately $200 e ^ { - 0.2 x }$ radios per month. The price at which the manufacturer should sell the radios to maximize the profit is

A) $10
B) $15
C) $18
D) $20