The diagram illustrates a synapse in a reflex arc. Which two neurones are shown, and in which direction does the neurotransmitter travel?
- Aneurone P: motor; neurone Q: relay; direction: P → Q
- Bneurone P: motor; neurone Q: sensory; direction: P → Q
- Cneurone P: relay; neurone Q: motor; direction: Q → P
- Dneurone P: relay; neurone Q: sensory; direction: Q → P