The Binding Energy of the First Level in an Atom

The binding energy of the first level in an atom is 2.2 10 -18 J, and the binding energy of the second energy level is 1.6 10 -18 J. What is the energy of the photon that is emitted if an electron moves from the second level to the first?

A) 3.3*10^-18 J
B) 3.5*10^-36 J
C) 1.4 J
D) 3.5*10^-18 J
E) 6.0*10^-19 J