Correct Option: D

Galaxies of great scholars like Asvaghosa (the Buddhist Writer), Nagarjuna (the philosopher), Samgharaksha (the chaplain), Mathara (the politician), Vasumitra (the Buddhist scholar), Charaka (the physician) and Agisala (the engineer) adorned the court of Kanishka. There were two important physicians in Kanishka's time namely Charaka and Susruta. Charaka was one of the principal contributors to the ancient art and science of Ayurveda, who is referred to as the Father of Medicine.