Answer:
(B). 50 cents
Explanation:
Marginal cost is the cost incurred by producing or purchasing one more unit of an item.
If Jordan buys two tacos and a medium drink, it will cost him $2 and 50 cents or 250 cents (80 + 80 + 90).
However, if he opts for the value meal of three tacos and a medium drink, that costs $3 (300 cents), then he would be purchasing one additional taco at a marginal cost of 50 cent.
Marginal cost of additional unit of taco = 300 cents - 250 cents = 50 cents.