$\overline{\mathrm{a}} \times \overline{\mathrm{a}^{1}}+\overline{\mathrm{b}} \times \overline{\mathrm{b}^{1}}+\overline{\mathrm{c}} \times \overline{\mathrm{c}^{1}}$ is
(a) $\frac{\bar{a} \times(\bar{b} \times \bar{c})}{[\overline{a c a}]^{2}}$
(b) $\frac{\bar{a} \times(\bar{b} \times \bar{c})}{[\text { aca }]}$
(c) 0
(d) None of these