  We use the StarTrack population synthesis code to discuss potential
progenitor models of SN Ia: single degenerate scenario, semi-detached double
white dwarf binary and double degenerate scenario. Using the most recent
calculations of accretion onto white dwarfs, we consider SN Ia explosions of
various white dwarfs in binary systems. We calculate the evolutionary delay
times from the zero age main sequence to the explosion, and verify which
scenarios can satisfy the constraints found by Strolger et al. (2004), i.e. a
delay time of 2-4 Gyrs. It is found that the semi-detached double white dwarf
binary model is inconsistent with observations. Only SN Ia progenitors in the
double degenerate scenario are compatible with observations in all tested
evolutionary models, with a characteristic delay time of about 3 Gyrs. If
double degenerate mergers are excluded as SN Ia progenitors, we find that the
single degenerate scenario may explain the observed delay times for models with
low common envelope efficiency. It is also noted that the delay time
distributions within the various tested SN Ia scenarios vary significantly and
potentially can be used as an additional constraint on progenitor models.
