The concept of marginal taxation is best exemplified by which one of the following? 1) Johnson's Retreat paid only $45,000 on total revenue of $570,000 last year. 2) Burlington Centre paid no taxes last year due to carryforward losses. 3) The Blue Moon paid $2.20 in taxes for every $10 of revenue last year. 4) Kirby's paid $120,000 in taxes while its primary competitor paid only $80,000 in taxes. 5) Mitchell's Grocer increased its sales by $52,000 last year and had to pay an additional $16,000 in taxes.