Calculate the wavelength of radiation that will provide a photon that would reach the energy threshold of iron of 6.878x10^-19 J.

• A. 5.847x10^-7 m
• B. 1.541x10^-6 m
• C. 2.888x10^-7 m
• D. 8.964x10^-6 m

Answer: (C)