A. There are thousands of species of colorful native wildflowers in
eastern North America, and only eleven species have orange
flowers.
B. There are thousands of species of colorful native wildflowers in
eastern North America, only eleven species have orange flowers.
C. There are thousands of species of colorful native wildflowers in
eastern North America only eleven species have orange flowers.
D. There are thousands of species of colorful native wildflowers in
eastern North America; only eleven species have orange flowers.
D, because it is using a semi-colon to connect two independent clauses that are closely related in topic. A should not have a comma, B is a comma splice, and C needs some sort of punctuation between the two clauses.
