Reagents which can be used to convert alcohols to carboxylic acids, are
(A) ${\mathrm{CrO}}_3-{\mathrm{H}}_2{\mathrm{SO}}_4$
(B) ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7+{\mathrm{H}}_2{\mathrm{SO}}_4$
(C) ${\mathrm{KMnO}}_4+\mathrm{KOH}/{\mathrm{H}}_3{\mathrm{O}}^{+}$
(D) $\mathrm{Cu},573 \mathrm{K}$
(E) ${\mathrm{CrO}}_3,{\left({\mathrm{CH}}_3\mathrm{CO}\right)}_2\mathrm{O}$
Choose the most appropriate answer from the options given below :