The correct answer is - D. all of these.
The collaboration between different types of organisms in nature is not something weird, it actually happens quite a lot. When we have a situation where two or more organisms have developed a relationship from which both of them benefit, we are talking about mutualistic symbiotic relationship.
The flowers and the pollinating animals are perfect example of this type of relationship. The flowers develop certain color or smell that will attract certain type of the pollinators. They will be attracted by the flower and pollinate it. The flower will become fertilized in that way, while the animal will get food source. Also, the pollinating animal will disperse the pollen in the surrounding area.