Cross-Tolerance Typically Occurs When

Cross-tolerance typically occurs when

A) tolerance to a drug is rapidly lost.
B) tolerance to a drug of one class, such as opiates, contributes to tolerance to a drug from a different class, such as barbiturates.
C) metabolizing enzymes for a drug of one class begin to metabolize a drug from a different class.
D) tolerance to a drug contributes to tolerance to a similarly acting drug.