What Flower Mechanism Would Help Prevent Pollination by a Foreign

Multiple Choice

What flower mechanism would help prevent pollination by a foreign plant species?

A) A pollen tube only grows inside the style of its own species.
B) The stigma is sticky mainly to its own species of pollen.
C) The timing of flowering keeps pollinators moving among a limited number of species.
D) Flowers attract a small number of specialized pollinators and, therefore, pollen is not spread equally to all available species of flowers.
E) All of the answer choices help prevent pollination by a foreign species.