A Contextual Stimulus Is

A contextual stimulus is:

A) An environmental event that is not part of the original conditioning, but has become associated with the US
B) A type of CS that occurs only in certain situations and produces a response whenever the organism is in that situation
C) A stimulus that precedes the delivery of a reinforcer, but only when certain environmental conditions are available
D) A stimulus that speeds up the process of habituating to unconditioned stimuli that frequently occur in that context