Asynapse between a motor neuron and a muscle cell uses the neurotransmitter acetylcholine. where is the acetylcholine produced and to where does it travel?

synaptic vesicles of the motor end plate; receptors on the axon
synaptic vesicles of the axon; receptors on the motor end plate.
receptors of the motor end plate; synaptic vesicles on the axon
receptors of the axon; synaptic vesicles on the motor end plate

It is produced in the receptors of the axon and it  travels trough the synaptic vesicles on the motor end plate.

Explanation:

Acetylcholine is produced by a series of enzymatic reaction in the neuron terminal, it is stored in small sacs called vesicles until an electrical impulse arrived and release them in the space among neurons called synapse.

When this neurotransmisor reaches another neuron, it is bonded in the acetylcholine receptors. The effect of this chemical substance is to contract the muscles like the heart muscles, by opening the sodium - potassium channel on it.

Hope this info is useful.

Receptors of the axon; synaptic vesicles on the motor end plate