With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: There are numerous methods available to synthesize MDMA via different intermediates. The original MDMA synthesis described in Merck's patent involves brominating safrole to 1-(3,4-methylenedioxyphenyl)-2-bromopropane and then reacting this adduct with methylamine. Most legal MDMA is synthesized using MDP2P (3,4-methylenedioxyphenyl-2-propanone) as a precursor. MDP2P in turn is generally synthesized from piperonal, safrole or isosafrole. One method is to isomerize safrole to isosafrole in the presence of a strong base, and then oxidize isosafrole to MDP2P. Another method uses the Wacker process to oxidize safrole directly to the MDP2P intermediate with a palladium catalyst. Once the MDP2P intermediate has been prepared, a reductive amination leads to racemic MDMA (an equal parts mixture of ("R")-MDMA and ("S")-MDMA). Relatively small quantities of essential oil are required to make large amounts of MDMA. The essential oil of "Ocotea cymbarum", for example, typically contains between 80 and 94% safrole. This allows 500 ;ml of the oil to produce between 150 and 340 grams of MDMA.
text_B: If you were involved in a clinical trial testing MDMA, is it likely that it was produced using MDP2P as a precursor?
YES.