What Is the Purpose of the Figures and Mithunas Around

What is the purpose of the figures and mithunas around the doorway of the Vishnu Temple at Deogarh?

A) To mark the transition between exterior world and sacred interior
B) To illustrate the episodes from the events in the saga of Vishnu
C) To invoke blessings and fertility for all who enter the temple
D) To serve as intermediaries to the god for people visiting the temple