Answer : The correct option is, (B) +0.34 V
Explanation :
To predict the spontaneity of a redox reaction :
To see whether a given redox reaction is feasible or not, the standard cell potential of the cell based upon the given redox reaction is calculated.
For a redox reaction to be spontaneous, the standard cell potential of the cell must be positive.
If the standard cell potential comes out to be negative, the direct reaction as given cannot take place, the reverse reaction may take place.
Hence, a standard cell potential +0.34 V describes a spontaneous redox reaction.