Cindy Abuses Barbiturates and She Continually Increases Her Doses

 Cindy abuses barbiturates and she continually increases her doses. What is the likely outcome of this practice for Cindy's health?

A) She is not at risk of overdose, because her body continually increases its tolerance to match her intake.
B) She is very likely to overdose, because some barbiturate effects show tolerance while others do not.
C) She is not at risk of overdose, because barbiturates do not have life-threatening effects, even at high doses.
D) She is very likely to overdose, because barbiturates do not produce tolerance.