Question

John stretched while his muscles were cold. Which negative effect could occur?

a.Blood might not flow to his limbs.
b.His strength could decrease quickly.
c.He could injure or pull a muscle.
d.Oxygen might not reach his muscles.

Answer 1

C. he could injure or pull a muscle

Answer 2

If John stretched while his muscles were cold, the negative effect that could occur is that C. he could injure or pull a muscle.
It is always important that your muscles are "heated" before you start exercising so as to avoid hurting yourself.