In studying "psychic secretions," pavlov focused his attention on the genetic history of the dog dog's thoughts and feelings events in the dog's environment behavior of the dog before and after feeding

Events in the dog's environment.

The secretion by the digestive glands in acknowledgment of stimuli correlated with the ingestion of food is called Psychic Secretion. such as the appearance and smell of food, the circumstances under which it is consumed is called Psychic Secretion.

Salivating to food in the mouth is reflexive, this involves no learning. However, dogs don't generally salivate at the perception of an empty bowl or the noise of footsteps. These unusual acknowledgments fascinated Pavlov, and hence he called the dogs as “psychic secretions”.

answer is b.shrapnel

by using  production possibilities graph.  opportunity costs are key expenses in financial matters and are utilized as a part of registering money saving advantage investigation of a venture. such expenses, be that as it may, are not recorded in the record books but rather are perceived in basic leadership by processing the money costs and their subsequent benefit or misfortune.