I think its B because Charlie is overweight and should start a exercise routine and diet but his caliper test doesn't make sense since his BMI is so high.
It would be C because he's doing a healthy diet unlike the others
The answer is : increased resistance need to be added to the muscles.
Muscle conditioning refer to muscle strength and endurance. In order to improve it, you need to put your muscle in a harsher condition in a harsher condition than it used to be, so your muscle could adjust to it. That's why you should keep increasing the resistance
