The feast includes a “variety of dishes,” so the sentence requires a word that means mixture or multitude. “Medley” and “mélange” both mean mixture. “Paucity” and “dearth” both mean scarcity, so that pair is at odds with the idea that there are many different dishes. “Rarity” could perhaps refer to the scent of dishes that are only made once a year, but “anomaly” refers to something that deviates from the norm, so these two words can’t be the correct pair