A ball-and-stick model displays a cubic lattice built from large copper-colored spheres. Much smaller carbon-colored spheres are located at the centers of several cubic voids in the lattice. Which statement best explains why the solid should NOT be classified as a substitutional alloy?
a) Because carbon is a nonmetal, substitution cannot occur in a metallic lattice.
b) Substitutional alloys require elements with nearly identical electronegativities; the large difference between the two elements precludes substitution.
c) The atomic radii of the two elements differ too greatly for one to replace the other at lattice positions.
d) A body-centered cubic lattice, such as the one shown, by definition cannot form substitutional alloys.