Explanation:Correct Answer: Calorific refers to the study or measurement of heat energy, especially in terms of its capacity to do work, and is a key concept in thermodynamics.
Other Options:
(B) Study of fruits - This is pomology.
(C) Study of faces - This could refer to physiognomy, but it’s not commonly associated with "calorific."
(D) Study of mercury - This would be more related to toxicology or chemistry.