2 is CORRECT. F2 may be expressed as F2 = SUM m(0,1,6,7) therefore
          F1 + F2 = SUM m(0,1,2) + SUM m(0,1,6,7) 
                  = m0 + m1 + m2 + m0 + m1 + m6 + m7 
                  = m0 + m1 + m2 + m6 + m7   (recall: x + x = x) 
                  = SUM m(0,1,2,6,7)