How can stiff and tight muscles result in back pain?

because If the muscles are dehydrated, overused, or suffer an acute injury, they tense up to prevent damage to these underlying structures. When they tense up, the nerves in these muscles lose their blood supply and send a pain response to the brain. This is the reason tense muscles create pain.

hope this helps

Explanation:

If the muscles are dehydrated, overused, or suffer an acute injury, they tense up to prevent damage to these  structures. When they tense up, the nerves in these muscles lose their blood supply and send a pain response to the brain.

Explanation:

Regular exercise helps keep muscles healthy and in good shape. If u dont get exercise then it will result in the stuff u see above.⬆️

b is the correct answer