Which of the following plants is known for its fragrant flowers?

The correct answer is that Azaleas are known for their fragrant flowers. They belong to the Rhododendron family and produce blooms that can exhibit a sweet and pleasant scent, making them popular in gardens and landscaping. Generally, fragrant flowers attract pollinators, and azaleas are no exception; many species have developed these aromas to encourage visits from bees and other insects.

In contrast, while some plants in other choices may have appealing flowers, they are not particularly noted for their fragrance. Cacti, for instance, are typically recognized for their unique shapes and the rarity of their blooms rather than any scent. Marigolds provide bright and cheerful flowers, often used for companionship in gardens to deter pests, but their fragrance is not deemed particularly strong or fragrant. Rhododendrons, though they share a close relationship with azaleas, can vary widely in scent from one variety to another, and many are not known for having a strong fragrance that would compete with that of azaleas.

Azaleas' reputation for fragrance makes them notable in discussions of flowering plants that attract attention with their scent.