Concept:The sa'y commemorates an important event in Islamic history.Explanation:Sa'y means striving or searching.It recalls the action of Hajar, the mother of Prophet Ismail, who ran between Safa and Marwah.She was searching for water for her infant son.Therefore, the sa'y is not merely exercise or a way to complete Hajj rituals.It is a symbolic act in memory of her search for water.Answer:B. in memory of search for water by Hajar