A community has 4,500 youths. If surveys show that 12% are involved in drug abuse, how many youths in the community are drug abusers?

To find 12% of 4,500: (12/100) × 4,500 = 0.12 × 4,500 = 540. Option A (450) represents 10% of 4,500, a common error of using the wrong percentage. Option B (504) and D (560) are plausible distractors from arithmetic errors. The correct answer is 540.