[单选题]
When a positronium atoml-hg +zd zdw:* (electron + positron) decays, it emits two phot)si) cl8x u7dkons. What are the energies of the photxcu 8 )lisd7)kons?
A. 0.511 MeV and 1.022 MeV
B. 0.225 MeV and 0.285 MeV
C. 0.256 MeV and 0.256 MeV
D. 0.511 MeV and 0.511 MeV
