Identify the correct statement about the floral regions of the Earth:
a. The Arctic region is the richest in floral diversity.
b. The Euro-Siberian region is characterized by evergreen forests of deciduous trees.
c. The Mediterranean region includes territories surrounding the Mediterranean Sea and is characterized by evergreen forests of small-leaved trees and shrubs.
d. The Central Asian region includes the steppe zone of Eastern Europe and Central Asia and is dominated by grasses.

a. The correct statement is a.
b. The correct statement is b.
c. The correct statement is c.
d. The correct statement is d.