A Horizontally Projected Beam of Electrons Travels At $55 \mathrm{~km} / \mathrm{s}$

A horizontally projected beam of electrons travels at $55 \mathrm{~km} / \mathrm{s}$ into the space between two horizontal, parallel plates. The plates are separated by $7.4 \mathrm{~cm}$ , and they are $12 \mathrm{~cm}$ long. The uniform electric field between the plates is $7.2 \mathrm{mV} / \mathrm{m}$ upward. If the beam enters the region at a height of $3.7 \mathrm{~cm}$ above the lower plate, at what height above the lower plate does the beam exit the region? The electron mass is $9.11 \times 10-31 \mathrm{~kg}$ .

A) $0.9 \mathrm{~cm}$
B) $2.3 \mathrm{~cm}$
C) $4.6 \mathrm{~cm}$
D) $3.4 \mathrm{~cm}$