A simplified atomic spectrum shows two emission lines. One line corresponds to a 1.89eV photon emitted when the atom drops from level 2 to level 1. The other corresponds to a 0.97eV photon emitted when the atom drops from level 3 to level 2. What is the energy of level 3 relative to level 1?
(a) 1.89eV
(b) 0.92eV
(c) 2.86eV
(d) 2.50eV