They are all answered already
Although both B and C would support the argument, I believe the correct answer in this case would be A.
At Jundi Shapur the best scholars west of China all gathered to think and study together. By the 600s, the doctors at the school were writing about a medicine from India named sharkara or, as the Persians called it, shaker—sugar. Indeed, scholars at Jundi Shapur invented new and better ways to refine cane into sugar.