Although Many Types of Plants Decreased in Diversity as Angiosperms

Although many types of plants decreased in diversity as angiosperms gained dominance, polypod ferns radiated in conjunction with the evolution of angiosperms. Why?

A) Angiosperms created new environments that ferns could inhabit.
B) Angiosperms and ferns could interbreed, increasing fern diversity.
C) Herbivores that once preyed on ferns began to target angiosperms.
D) In response to angiosperms, ferns developed secondary growth.
E) All of these choices are correct.