A Pigeon Is Reinforced for Pecking a Yellow, but Not

Multiple Choice

A pigeon is reinforced for pecking a yellow, but not a purple, key. When tested with colors similar to yellow, responding falls off gradually as the color becomes more different. Which of the following statements is true?

A) According to theories of attention like that of Mackintosh, this gradient would probably have been much flatter if there had been no S^Δ and no opportunity to learn the exact features of light that make it a good predictor.
B) This gradient is a natural function of the degree of similarity between stimuli.
C) The gradient would have been much steeper if there had been no S^Δ.
D) The gradient should not be affected by an S^Δ unless the S^D and S^Δ are very similar.