Which of the Following Flower Mechanisms Would Help Prevent Pollination

Multiple Choice

Which of the following flower mechanisms would help prevent pollination by a foreign species?

A) A pollen tube only grows in the style of its own species.
B) The stigma is sticks only to its own species of pollen.
C) The timing of flowering varies by species.
D) Flowers attract a small number of specialized pollinators.
E) All of the answer choices describe mechanisms that reduce the chance of pollination by a foreign species.