An Electron Is Released from Rest at a Distance Of 9.00

An electron is released from rest at a distance of $9.00 \mathrm {~cm}$ from a fixed proton. How fast will the electron be moving when it is $3.00 \mathrm {~cm}$ from the proton? $\left( k = 1 / 4 \pi \varepsilon _ { 0 } = 8.99 \times 10 ^ { 9 } \mathrm {~N} \cdot \mathrm { m } ^ { 2 } / \mathrm { C } ^ { 2 } , e = 1.60 \right.$ $\left. \times 10 ^ { - 19 } \mathrm { C } , m _ { \text {electron } } = 9.11 \times 10 ^ { - 31 } \mathrm {~kg} , m _ { \text {proton } } = 1.67 \times 10 ^ { - 27 } \mathrm {~kg} \right)$

A) $4.64 \times 10 ^ { 5 } \mathrm {~m} / \mathrm { s }$
B) $75.0 \mathrm {~m} / \mathrm { s }$
C) $1.06 \times 10 ^ { 3 } \mathrm {~m} / \mathrm { s }$
D) $130 \mathrm {~m} / \mathrm { s }$
E) $106 \mathrm {~m} / \mathrm { s }$