The requirements for one type of atom to substitute for another in a solid solution are:
All substitutions must be limited to the same element.
An atom must be similar in size.
The substituting atom must be from the same period.
The substituting atom must be from the same group.
An atom must be identical in size.

the atom must be similar in size and it must be from the same group.

Explanation:

A solid solution is essentially a multicomponent system which is composed of a mixture of two or more elements sharing the same crystal lattice. Alloys are solid solutions.

The requirement for one type of atom to substitute for another in a solid solution are two fold

1) The atom must be similar in size

2) The substituting atom must be from the same group.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.

it should be all of them because it asks if you included all of those in your answer

explanation: