The Hall Affect Is Used to Measure the Carrier Density $\mu$

The Hall affect is used to measure the carrier density of a thin sheet of electrons.When a current of 8.0 $\mu$ A flows through the length of the electron sheet,which is 1.2-mm long,0.27-mm wide and 12-nm thick,a magnetic field of 0.75 T perpendicular to the sheet produces a potential difference of 0.53 mV across the width of the sheet.What is the carrier density in the electron sheet?

A) 4.81 * 10¹⁸ m^-3
B) 5.90 * 10¹⁹ m^-3
C) 2.62 * 10²⁰ m^-3
D) 5.90 * 10²⁴ m^-3
E) 6.74 * 10²⁵ m^-3