If the De Broglie Wavelength of an Electron Is $380 \mathrm {~nm}$

Multiple Choice

If the de Broglie wavelength of an electron is $380 \mathrm {~nm}$ , what is the speed of this electron? (melectron $\left. = 9.11 \times 10 ^ { - 31 } \mathrm {~kg} , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

A) $4.1 \mathrm {~km} / \mathrm { s }$
B) $1.9 \mathrm {~km} / \mathrm { s }$
C) $3.8 \mathrm {~km} / \mathrm { s }$
D) $2.0 \mathrm {~km} / \mathrm { s }$
E) $5.2 \mathrm {~km} / \mathrm { s }$