D agreed to sell a controlled substance, cocaine, to Keith Hatcher. Hatcher was cooperating with the government. Hatcher gave D $200, and D gave Hatcher approximately two grams of what was supposed to be cocaine. The 'cocaine' turned out to be acetaminophen. Acetaminophen is not a controlled substance. D was convicted of delivering a simulated controlled substance with respect to a substance represented to be cocaine, in violation of Iowa Code section 204.401(2)(a) (1987). D was convicted and appealed. D contends he cannot be guilty of delivering a simulated controlled substance when in fact he (and everyone else) believed he was delivering cocaine.