What Is the Wavelength of the Photon Emitted When an Electron

Multiple Choice

What is the wavelength of the photon emitted when an electron in a hydrogen atom which is in the initial state $n = 4$ jumps to the final state $n = 2$ ? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } , 1 \mathrm { eV } = \right.$ $1.60 \times 10 ^ { - 19 } \mathrm {~J}$ )

A) $556 \mathrm {~nm}$
B) $312 \mathrm {~nm}$
C) $486 \mathrm {~nm}$
D) $243 \mathrm {~nm}$
E) $609 \mathrm {~nm}$