The final products of the reaction of carbonyl metalates $\left[\mathrm{V}(\mathrm{CO})_{6}\right]^{-}$ and $\left[\mathrm{Co}(\mathrm{CO})_{4}\right]^{-}$ with $\mathrm{H}_{3} \mathrm{PO}_{4}$ respectively, are
(a)$\mathrm{V}(\mathrm{CO})_{6}$ and $\mathrm{HCo}(\mathrm{CO})_{4}$
(b)$\mathrm{HV}(\mathrm{CO})_{6}$ and $\mathrm{Co}_{2}(\mathrm{CO})_{8}$