Given a,b,c

a,b,c in the domain of all positive integers, in a proof to the theorem a3+b3+c3a2b+b2c+c2aa3+b3+c3a2b+b2c+c2a, we may assume without loss of generality that: A. ab,acab,ac B. ab,bcab,bc C. ac,cbac,cb D. ac,bc