When a VI Schedule Was Yoked to a VR Schedule

Multiple Choice

When a VI schedule was yoked to a VR schedule so that pigeons on the VI schedule had the same opportunity to earn reinforcement as birds on the VR schedule,

A) subjects in both groups showed similar rates of responding.
B) subjects in the VI group pecked more vigorously than those in the VR group.
C) subjects in the VR group pecked more vigorously than those in the VI group.
D) subjects in the VR group showed initially high levels of responding but their response rate quickly dropped to the rate of the VI subjects.