Correct Answer - B
Since oxidation takes places at anode whikle reduction occurs at cathode, there are three ways to calculate the `emf` of an electrochemical cell:
`E_("cell")^(@) = E_("anode")^(@)("oxid")+E_("cathode")^(@)("red")`
or `E_("cell")^(@) = E_("anode")^(@)("oxid")-E_("cathode")^(@)("oxid")`
or `E_("cell")^(@) = E_("cathode")^(@)("red")+E_("anode")^(@)("oxid")`