Final answer:
The effects of ecstasy, according to the question's options, last up to 6 hours, which is option a. However, the reference states that the effects are at least seven hours, and it can take up to 32 hours for complete elimination from the body.
Step-by-step explanation:
The effects of ecstasy can last for up to 6 hours, which means the correct answer to the question is a. 6 hours. Therefore, based on the reference provided, the effects of ecstasy are c. at least seven hours, which does not align with the options given in the original question. It's important to note that while the primary effects may last only a few hours, the drug can have longer-term effects on the body and brain, and it can take up to 32 hours for ecstasy to be completely eliminated from the body.