Who is the greatest angel as per Islam?

a) Hazrat Mickael (A.S)

b) Hazrat Israfil (A.S)

c) Hazrat Jibraeel (A.S) 

d) Hazrat Izrael (A.S)

Hazrat Jibrael (A.S) is the greatest angel as per Islam. He used to bring revelations to the Holy Prophet (PBUH). He is blessed with 600 wings as per Hadis.