In a Two-Component Alloy, the More Abundant Metal Can Be

Multiple Choice

In a two-component alloy, the more abundant metal can be thought of as the solvent while the less abundant metal can be thought of as the solute.Which of the following is an explanation of why an alloy is often harder than either of the pure elements?
I.In a homogenous substitutional alloy, the solute atoms slightly distort the crystal structure, making it hard for atoms to slip past one another.
II.In a heterogeneous alloy, small regions rich in the solute atom can disrupt the crystal lattice, making it hard for atoms to slip past one another.
III.When solute atoms occupy interstitial sites, they can prevent the atoms in the crystal structure from slipping past one another.

A) only I
B) only II
C) only III
D) I or II
E) I, II, or III