(c)
$Zn(s) + 2H^{+}(aq) \rightleftharpoons {Zn}^{2 +}(aq) + H_{2}(g)$
$E_{cell} = E_{cell}^{{^\circ}} - \frac{0.059}{2}\log\frac{\left\lbrack {Zn}^{2 +} \right\rbrack}{\left\lbrack H^{+} \right\rbrack^{2}}$
When $H_{2}{SO}_{4}$ is added then $\left\lbrack H^{+} \right\rbrack$ will increase therefore $E_{cell}$ will also increase and equilibrium will shift towards right