Greek scholars started a branch of study called philosophy which?

The migration waves of Byzantine scholars and émigrés in the period following the Crusader sacking of Constantinople and the end of the Byzantine Empire in 1453, is considered by many scholars key to the revival of Greek and Roman studies 

The answer to this question is  c. pharmaceutical accumulation  reclaimed water refers to the water that being used again after it already  used for agricultural purposes.this type of water often contains pharmaceutical accumulation because of the chemical fertilizer that is used for the plants is absorbed into the water.