All of the following statements about efficacy and potency are true EXCEPT:
a) Efficacy is usually a more important clinical consideration than potency
b) Efficacy is the maximum effect of a drug
c) Potency is a comparative measure, refers to the different doses of two drugs that are needed to produce the same effect
d) The ED50 is a measure of drug’s efficacy
d) The ED50 is a measure of drug’s efficacy