A wire of length $0.35\,\text{m}$ carries an electric current of $12\,\text{A}$. The mean drift speed of the free electrons (charge carriers) in the wire is $5.0 \times 10^{-4}\,\text{m s}^{-1}$. Determine how many free electrons are in the wire?
- A$1.3 \times 10^{16}$
- B$5.3 \times 10^{22}$
- C$1.5 \times 10^{23}$
- D$4.3 \times 10^{23}$