Nagarjuna and Charaka were patronised by which ruler?
Explanation
Traditional historical accounts associate the Kushana emperor Kanishka with the patronage of Buddhist intellectuals including Ashvaghosha, Nagarjuna and the physician Charaka, though individual biographies contain legendary elements. This makes the selected option factually and chronologically appropriate. Samudragupta, Harshavardhana and Chandragupta II belonged to different centuries and courtly networks. The incorrect choices are plausible only at a broad level; each belongs to a different author, ruler, monument, office, text or historical phase. Reading the exact wording and matching it with the relevant source prevents shifted-field errors.