To warm up before a run, david begins by completing quad and hurdler's stretches which of these accurate evaluates his choice of warm-up activities?
a)these activities are appropriate because they prepare muscles for intense movement.
b)these activities are not appropriate because the musces stretched are not warm yet.
c)these activities are appropriate because they make the leg muscles more flexible.
d)these activities are not appropriate because they stretch muscles not used in the exercise.