Heroin and Methadone Are Cross-Tolerant.What Does This Mean

Multiple Choice

Heroin and methadone are cross-tolerant.What does this mean?

A) They act on the same neurotransmitter receptors and, thus, a person addicted to one drug may become addicted to the other.
B) They each produce the same level of high in users.
C) They each produce a significantly different type and level of high in users.
D) They do not act on the same neurotransmitter receptors; however, the level of tolerance developed will automatically cause a generalization to the other drug.