$\text{ Experimentally it was found that a metal oxide has formula }{\mathrm{M}}_{0.98}\mathrm{O}.\text{ Metal }\mathrm{M}\text{, is present as }$${\mathrm{M}}^{2+}\text{ and }{\mathrm{M}}^{3+}\text{ in its oxide. Fraction of the metal which exists as }{\mathrm{M}}^{3+}\text{ would be : }$

• A

  7.01% 

• B

  4.08% 

• C

  6.05%

• D

  5.08%