Answer: The option that is true regarding Carl's use of substances is D) All of these choices are true.
Step-by-step explanation: All of the choices provided about Carl's use of substances are true. First, he shows that he has characteristics of addictive behaviour when he denies that he has a problem with drug use, when he boasts about his capacity to drink alcohol, and when he dismisses the risks of mixing alcohol and drugs. Moreover, Carl has a substance abuse problem he desires to drink and use drugs day and night and even to mix the substances. He also has a substance dependence problem because, when he is not drinking, he is using "speed" and, when he needs to sleep, he takes Valium. In that way, Carl has both substance abuse and substance dependence problems and he also behaves as an addict.