The correct option is B Cu rod in CuSO4 solution
One of the most popular galvanic cell is the Daniell cell. Spontaneous redox reaction is used here to produce electricity.
The redox reaction occur in Daniell cell is
Zn(s)+Cu2+(aq)→Zn2+(aq)+Cu(s)
Anode half cell is zinc rod in zinc sulphate solution.
Anodic half cell reaction is
Zn(s)→Zn2+(aq)+2e−
Cathode half cell is copper rod in copper sulphate solution.
Cathodic half cell reaction is
Cu2+(aq)+2e−→Cu(s)
Thus, option (b) is correct.