Rose flower does not contain nectar. It provides the visiting insect with.
Insect and other animal pollinators obtain food in the form of protein-rich pollen and it is from the flowers that they visit. The flowers are getting services of pollinators carrying pollen from one flower to another.
While food is often sufficient for the pollinators, the flowering plants also attract the pollinators using petal shapes, scents, and colors. Pollination syndromes are being described to depict the attraction of certain types, shapes, colors, and fragrances of flowers with a range of pollinators. The correct answer is edible pollen.
The correct option is C.