A metal wire is $3.0\,\text{m}$ long and is made from a material with resistivity $4.9 \times 10^{-7}\,\Omega\,\text{m}$. A potential difference (p.d.) of $12\,\text{V}$ is placed across the wire, causing a current of $1.4\,\text{A}$ to flow. Calculate the cross-sectional area of the wire.
- A$1.2 \times 10^{-7}\,\text{m}^2$
- B$1.7 \times 10^{-7}\,\text{m}^2$
- C$1.1 \times 10^{-6}\,\text{m}^2$
- D$1.3 \times 10^{-5}\,\text{m}^2$