Principal alloying elements of cast tool alloys which have very high wear resistance & high temperature strength are ?

(A) Cobalt, chromium & tungsten ()
(B) Cobalt, chromium & nickel (X)
(C) Molybdenum, tungsten & chromium (X)
(D) Cobalt, zirconium & molybdenum (X)

Answers: Principal alloying elements of cast tool alloys which have very high wear resistance & high temperature strength are  Cobalt, chromium & tungsten.