The constituent common to duralumin and alnico is

A.

Co

B.

Mn

C.

Al

D.

Mg

Correct answer is C

Constituents of duralumin are: Al, Cu, Mg, Mn.

Constituents of Alnico are: Al, Ni and Co

In 1909, the alloy of duralumin was discovered by Alfred Wilon consisting of 94% Al, 4% Cu, 1% Mg and 1% Mn(Manganese)

Alnico is an acronym referring to a family of iron alloys which in addition to iron are composed primarily of Al, Ni and Co.