Schools really don't care where you applied or how many schools you applied to unless you applied EDP.
They know, that unless you apply EDP, you have applied to more schools.
Seriously if they ask... tell them and move on. Don't apologize for applying elsewhere. You usually have valid reasons to have applied to certain other schools. Some may be closer to family, some in a cheaper area to live, some may have better programs, some may offer you money, etc...... All valid reasons to apply to a list of other schools.