The firm has total fixed costs of $9 and a constant marginal cost of $3 per unit. The firm will maximize profit with a. 9 units of output. b. 15 units of output. c. 21 units of output. d. 30 units of output.

b. 15 units of output.

Explanation:

information regarding sales price and quantity demanded is missing, so I looked it up (see attached file):

units              sales revenue            total costs            profits

9                       $216                            $36                     $180

15                      $270                           $54                     $216

21                      $252                           $72                     $180

30                     $90                             $99                     ($9)

for submitting your question to

the answer to your question is : c) a government agency or homeowner

due to his line of work, he is most likely employed by a government agency or homeowner due to the other choices not being logical haha.