Subjects' Responses Are Likely to Demonstrate a Sharper or Steeper

Multiple Choice

Subjects' responses are likely to demonstrate a sharper or steeper generalization gradient if the researchers use

A) one intense stimulus as the S^D or training stimulus.
B) one intense stimulus as the S^D and one weak stimulus as the S^Δ training stimulus.
C) two intense stimuli as the S^D and S^Δ training stimuli.
D) two similar stimuli as the S^D and S^Δ training stimuli.