GMAT Reading Comprehension (RC) | Re: Scientific advances in the latter half of the twentieth

Explanation for #3:

"(D) Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin."

It may seem Out of Scope at first -- why would we bring in some other drug in the "argument." Tricky as it is, the answer choice actually implies that there are other hallucinogenic drugs other than LSD that still perform their main function--make one hallucinate--despite its inability to inhibit serotonin (unlike LSD).

Hence, if it is true that there are other drugs
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