Read Each Textbook Excerpt and Then Answer the Questions That

Read each textbook excerpt and then answer the questions that follow.
Earth supports an amazing diversity of flowering plants, from tender marigolds to prickly rose bushes, from short grasses to towering oaks. Overall, however, all flowering plants can be placed into one of two large groups, called monocots and dicots. Monocots include lilies, daffodils, tulips, palm trees, and a wide variety of grasses (not only the familiar lawn grasses but also wheat, rice, corn, oats, and bamboo) . Dicots include virtually all "broad-leafed" plants, such as deciduous trees and bushes, most vegetables, and many flowers in fields and gardens.
-The primary organizational pattern used in this excerpt is

A) time sequence.
B) classification.
C) listing.
D) cause-effect.