c
Resistance of wire $(R)=\rho \frac{1}{A}$
If wire is bent in the middle then
$l'=\frac{1}{2}, A^{\prime}=2\, A$
$\therefore $ $\text { New resistance, } \mathrm{R}^{\prime} =\rho \frac{l^{\prime}}{\mathrm{A}^{\prime}} $
$=\frac{\rho \frac{l}{2}}{2\, A}=\frac{\rho l}{4\, A}=\frac{R}{4}$