Concept:Eid-ul-Adha is an Islamic festival that commemorates the obedience of Prophet Abraham, who was willing to sacrifice his son for Allah.Explanation:Eid-ul-Adha is known as the Festival of Sacrifice.It recalls the event in which Abraham proved his readiness to sacrifice his son in obedience to Allah.Allah then provided a ram to be sacrificed instead.The other options are incorrect because the end of Ramadan is marked by Eid-ul-Fitr, not Eid-ul-Adha.Answer:A. mark Abraham’s sacrifice to Allah