During Mesolithic age, climate was getting warmer and the diet of _________ was also undergoing change.

The correct option is D Homo sapiens sapiens
During Mesolithic age, climate was getting warmer and the diet of Homo sapiens sapiens was also undergoing change. The Mesolithic Age, which means Middle Stone Age, was the second part of the Stone Age. This age is characterized by the use of Microliths (small bladed stone tools).