The concept of marginal taxation is best exemplified by which one of the following?

a. Kirby's paid $120,000 in taxes while its primary competitor paid only $80,000 in taxes
b. Johnson's Retreat paid only $45,000 on total revenue of $570,000 last year
c. Mitchell's Grocer increased its sales by $52,000 last year and had to pay an additional $16,000 in taxes
d. Burlington Centre paid no taxes last year due to carry forward losses
e. The Blue Moon paid $2.20 in taxes for every $10 of revenue last year

Ans: c. Mitchell's Grocer increased its sales by $52,000 last year and had to pay an additional $16,000 in taxes