Mr Broderick Is Trying to Teach His Daughter Erin the Concept

Mr. Broderick is trying to teach his daughter Erin the concept trout. For Erin to learn to recognize trout as quickly as possible, which one of the following things should Mr. Broderick do?

A) Show her different kinds of trout (e.g., rainbow, brook) at different times.
B) Show her one kind of trout (e.g., rainbow) and one kind of non-trout (e.g., sunfish) both at the same time.
C) Show her different kinds of trout (e.g., rainbow, brook) and different kinds of non-trout (e.g., sunfish, salmon) all at the same time.
D) Show her different kinds of trout (e.g., rainbow, brook) first, then show her different kinds of non-trout (e.g., sunfish, salmon) on a later occasion.