) The energy per gram produced by fusion is similar for He, C, and 0 burning. However, the rate of neutrino losses increases markedly. Assume that for each of these burning stages the energy per gram of material released is 5x10 17 erg g-l. The photon luminosity required to maintain the stability of the star is 1x105 LO. If each stage has 1.5 MG of fuel available, calculate: A) the lifetime of He burning for a neutrino energy loss rate of 1x10 3 erg g-1 s-1 B) the lifetime of C burning for a neutrino energy loss rate of 1x107 erg g-1 s-1 C) the lifetime of O burning for a neutrino energy loss rate of 1x10 10 erg g-1 s-1