The high mass stars in cluster A have been born, left the main sequence, become red giants at least once, and long since died.
Helium flashes occur in low-mass red giants whose helium ash inner cores have become degenerate.
Stars with masses more than about 2-3 times the mass of the sun never have degenerate helium cores, so they would have no helium flashes. And since no low mass stars have yet formed, no helium flashes would have occurred yet. Neither moderate nor low mass stars have shown up yet in cluster B. Probably not, and here's why. Three solar masses is the upper limit for the formation of white dwarfs. First, match the luminosities to see if there are any candidates.