Marie: I gave the cashier at my local convenience store a 10-dollar bill to pay for my purchase, and he mistakenly gave me change for a 20-dollar bill.
Your task
Describe how the argument proceeds — the technique it uses to reach its conclusion.
Common trap
Answers that describe a method the argument doesn't actually use.
Winning move
Track the role each statement plays, then match that to the choice describing the same moves.