Answer:
D. $3.
Explanation:
Use following values to calculate the marginal revenue
Price ____ Quantity Demanded
$7 _______ 1
$6 _______ 2
$5 _______ 3
$4 _______ 4
$3 _______ 5
Working
Price ____ Quantity Demanded ___ Total revenue __ Marginal Revenue
P ___________ Q ________________ P x Q ____ Additional revenue
$7 ____________ 1 _________________ $7 _____ $7
$6 ___________ 2 _________________ $12_____ $5
$5 ___________ 3 _________________ $15 _____ $3
$4 ___________ 4 _________________ $16_____ $1
$3 ___________ 5 _________________ $15 _____ -$1