What happens to an enzyme after it has completed a reaction? A. The enzyme is folded.
B. The enzyme is reused.
C. The enzyme is denatured.
D. The enzyme is destroyed.

The enzyme will always return to it's original state at the completion of the reaction . In other words the enzyme is reused.

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.