The results obtained when the finely divided metal powders of P, Q, R and S are added to the aqueous solutions of different metal nitrates are given below: 

Displacement = √, No reaction = x

[Given: $$E^\circ_{\text{Ag}^+/\text{Ag}} = 0.80$$ V, $$E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76$$ V, $$E^\circ_{\text{Ni}^{2+}/\text{Ni}} = -0.25$$ V and $$E^\circ_{\text{Pb}^{2+}/\text{Pb}} = -0.13$$ V].
If these elements are to be arranged as per their positions in the electrochemical series, then which of the following will represent the above set of observations