The exercise that uses your body weight for resistance is:
B. Push-ups
Push-ups are a great example of a bodyweight exercise where you use your own body weight as resistance to strengthen and tone your muscles. Here's how to do a basic push-up:
1. Start in a plank position with your hands placed slightly wider than shoulder-width apart.
2. Lower your body by bending your elbows until your chest nearly touches the ground.
3. Push yourself back up to the starting position by straightening your arms.
By performing push-ups regularly, you can work multiple muscle groups including your chest, shoulders, triceps, and core. It's a versatile exercise that can be modified to suit different fitness levels and goals.