Answer: the answer is a
Explanation: tell me if it is
 
        
                    
             
        
        
        
The human movement is 4
exercises that use body weight is 5
contracting muscle is 12
holding a contraction is 8
decreasing the angle is 6
strengthening is 3
increasing is 7
lengthening of a muscle is 10
maximum amount of force is 1
isolating muscles is 15
undesirable movements is 14
shortening muscles is 9
sustained contraction is 2
opposing action is 13
increasing the weight is 16
        
             
        
        
        
Answer: d
 
Explanation:
Because it's quick easy and efficient so you can have easy access to it and  all you use is your toes and calves.