Answer:
D. Marginal revenue for producing the 9 units is $15
Step-by-step explanation:
TR(8) = $48
TR(9) = $63
MR(9) = TR(9) - TR(8) = $63 - $48 = $15
AR(8) = TR(8) / 8 = $48/8 = $6
AR(9) = TR(9)/9 = 63/9 = $9
Note: TR=Total revenue, AR= Average Revenue and MR=Marginal Revenue
So, the only correct option is option d