Passage Summary: Self-pollinating flowers have a clear reproductive edge because they don't need insects to reproduce, leading to more seeds over time. Despite this advantage, they are still much less common than the other variety.

Reasoning: Self-pollinating primroses produce more seeds on average than non-self-pollinating ones and are otherwise identical, yet they remain rare in the population.

Analysis: The paradox here is a biological one: why does a plant with a clear reproductive advantage (more seeds) fail to become the dominant type? We need to find a piece of information that explains why those extra seeds don't translate into a larger population of adult plants. Perhaps the seeds from self-pollination are less likely to survive, or perhaps the plants themselves are more susceptible to disease. Look for an answer that introduces a disadvantage to self-pollination that offsets the high seed count, effectively leveling the playing field or explaining the rarity.