When stretching, you should: a
work on a specific muscle group slowly and at one time
b
always do shoulders and legs first
c
compete with others to see who is more flexible
d
have the same degree of strength in all joints

work on a specific muscle group slowly and at one time

Explanation:

When you do stretches, usually you are targeting a specific point of your body, and therefore that makes it true, it also benefits more to do one slowly and at a time. Hope this helped!