Omar has been snorting gradually increasing amounts of heroin for more than one year and always gets ...

Omar has been snorting gradually increasing amounts of heroin for more than one year and always gets high in the bedroom of his house. He is at a party downtown and is offered some heroin.
 
  What issue should he consider before deciding to use heroin at the party?
   a) He may have developed behavioral tolerance, which could cause him to have an overdose if he uses in a different environment than his bedroom
  b) He may have developed behavioral tolerance, which could cause him to require more of the drug to feel the same effect if he uses in a different environment than his bedroom.
  c) He may have developed physical dependence, which could cause him to have an overdose if he uses in a different environment than his bedroom.
  d) He may have developed psychological dependence, which could cause him to require more of the drug to feel the same effect if he uses in a different environment than his bedroom.