The Primary Reason for Otto Loewi Conducting His Experiment Was

The primary reason for Otto Loewi conducting his experiment was:

A) to determine if electrical stimulation could be used to reinforce behavior.
B) to determine if stimulation of the vagus nerve could affect heart rate.
C) to determine if neurotransmission was electrical or chemical.
D) to determine if acetylcholine was a neurotransmitter.