Final answer:
The type of error in the given argument is affirming the consequent (c). Affirming the consequent is an invalid deductive inference form in which the truth of the consequent is affirmed to infer the truth of the antecedent.
Step-by-step explanation:
The type of error in the given argument is affirming the consequent (c). Affirming the consequent is an invalid deductive inference form in which the truth of the consequent is affirmed to infer the truth of the antecedent. In this case, the student is making the error of assuming that since they can swim, they must have taken swimming lessons. However, there could be other factors or ways of learning how to swim without taking formal lessons.