Acetylcholinesterase:

1. helps in binding of acetylcholine to its receptors.

2. catalyzes the synthesis of acetylcholine from acetate and choline.

3. stimulates receptors within the postsynaptic membrane.

4. breaks down acetylcholine.

Assertion: Calmodulin plays an important role in excitation contraction (EC) coupling and the initiation of the cross-bridge cycling in smooth muscle.
Reason: Troponin is not found in the smooth muscles.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.