Which of the following has a negative temperature coefficient of resistance?

For a metallic wire,the ratio of voltage to corresponding current is

This question contains statement-$1$ and statement-$2$. Of the four choices given after the statements,choose the one that best describes the two statements.
statement-$1$: The temperature dependence of resistance is usually given as $R=R_{0}(1+\alpha \Delta t)$. The resistance of a wire changes from $100 \; \Omega$ to $150 \; \Omega$ when its temperature is increased from $27^{\circ} C$ to $227^{\circ} C$. This implies that $\alpha=2.5 \times 10^{-3} /^{\circ} C$.
statement-$2$: $R=R_{0}(1+\alpha \Delta t)$ is valid only when the change in the temperature $\Delta t$ is small and $\Delta R=(R-R_{0}) << R_{0}$.

$A$ wire of a certain material is stretched slowly by $10\%$. Its new resistance and specific resistance become respectively:

The length of a metallic wire is increased by $20 \%$ and its area of cross-section is reduced by $4 \%$. The percentage change in resistance of the metallic wire is $.......$ (in $\%$)

For which material does resistivity decrease with an increase in temperature?