Which type of observational studies is the following an example of: in the situation
of clever hans (the horse), the owner believed he had taught his horse problem
solving skills. the owner would as a math question and the horse would respond
with a series of hoof stomps that matched the correct answer researchers evaluated
this happening, finding that the horse had just learned what physical cues his owner
was showing to know when he had reached the correct number of stomps. it was an
example of conditioning, not that the horse actually knew how to do math.

a) experimental
b) survey
c) case study
d) naturalistic observation