Dave's Consumer Surplus on Movie Rentals Per Week

Multiple Choice

Dave's Consumer Surplus on Movie Rentals per Week
(yes,we know no one rents movies anymore,but it makes a good example!)
TABLE 6-2
-Refer to Table 6-2.How many movies will Dave rent per week such that the consumer surplus on the last unit is zero?

A) 1
B) 3
C) 5
D) 6
E) 7