Final answer:
The healthy range for curl ups for 13-year old males is 20-30 repetitions. Hence the correct answer is option B
Step-by-step explanation:
The healthy range for curl ups for 13-year old males is 20-30 repetitions, which corresponds to option B. Curl ups, also known as crunches, are exercises that target the abdominal muscles. These exercises involve lying flat on your back, bending your knees, and raising your upper body off the ground by contracting your abdominal muscles. Performing 20-30 curl ups in a row is considered a healthy range for 13-year old males to improve and maintain abdominal strength and endurance.
Hence the correct answer is option B