Over time, a particular plant has developed a longer stamen. Which of the following is a possible advantage of having a longer stamen?
A. A longer stamen could ensure that an insect brushes against an anther and picks up pollen.
B. A longer stamen could ensure that the flower produces more nectar.
C. A longer stamen could ensure that pollen could reach the ovary and fertilize the egg.
D. A longer stamen could ensure that the developing flower is well protected.