As every mechanic knows, different engine problems can be identified by their effects on car performance. Thus, different brain disorders can be identified by their effects on mental acts, such as counting and sentence formation. Which one of the following most accurately describes a technique used in the author's argument?

Select one:

a. It cites evidence from a questionable source to support its conclusion.

b. It directs the argument at the proponent of a claim rather than at the claim itself.

c. It relies on an analogy to support its conclusion.

d. It relies on circular reasoning to advance the argument.

e. It appeals to an authority