In a Compton Scattering Experiment, the Scattered Photon Has a Wavelength

Multiple Choice

In a Compton scattering experiment, the scattered photon has a wavelength of $6.55 \mathrm{pm}$ . If the scattering angle is $50^{\circ}$ , what was the wavelength of the incident photon?

A) $0.868 \mathrm{pm}$
B) $7.42 \mathrm{pm}$
C) $3.28 \mathrm{pm}$
D) $5.68 \mathrm{pm}$
E) $2.43 \mathrm{pm}$