Which of the Following Demonstrates the Law of Supply

Which of the following demonstrates the law of supply?

A) When leather became more expensive, belt producers decreased their supply of belts.
B) When car production technology improved, car producers increased their supply of cars.
C) When sweater producers expected sweater prices to rise in the near future, they decreased their current supply of sweaters.
D) When ketchup prices rose, ketchup sellers increased their quantity supplied of ketchup.