First Principles Thinking: Line Amount ÷ Total Outflows
A is correct. The outflow approach divides each cash outflow by total cash outflows. Here, cash paid to suppliers = 9,000 and total outflows = 20,000, so the percentage is 9,000 ÷ 20,000 = 0.45 = 45%. Other lines (3,000 for other expenses, 8,000 for remaining items) would each be similarly scaled. The readings Acme example applies exactly this calculation to show suppliers, employees, and other payments as proportions of total outflows. Hook: "common-size % = item cash ÷ total cash bucket."
B is incorrect: 30% would result from dividing 6,000 by 20,000, confusing supplier payments with another outflow.
C is incorrect: 60% would require 12,000 ÷ 20,000, overstating the weight of supplier payments and failing to match the actual line amount.