A student observed four plants (A, B, C, D). The number of stamens in a flower of 'A' is equal to those of a flower of 'B'. Out of the ten stamens arranged in two bundles in a flower of 'C', the stamen number in the bundle which possesses most of the stamens is three times to that of inner whorl of a flower of 'A'. In 'D', the number of stamens is equal to those present in the inner whorl of plant 'B;. Identify A, B, C and D plants respectively.