An axonal growth cone has reached a muscle fiber and is forming a neuromuscular junction. Which of the following events does NOT normally occur in this process?

A) Agrin secreted from the growth cone serves as a signaling molecule affecting the muscle cell.
B) LRP4 on the surface of the growth cone serves as a signaling molecule affecting the muscle cell.
C) Synaptic vesicles containing the neurotransmitter acetylcholine appear in the growth cone.
D) Acetylcholine receptors cluster on the muscle cell plasma membrane at the junction.
E) A thin layer of basal lamina forms at the cleft between the two cell membranes at the junction.