If the equations `(b + c)x + (c + a)y + (a + b)z = 0; cx + ay + bz = 0; ax+by+cz=0` have non-zero solutions then a relation and `a, b, c` is (A) ` a=b=c=0` (B) `a=2b=3c` (C) `a=b=c!=0` (D) `a+2b+3c=0`