Ferns, whisk ferns, and lycopods are all considered to be
a. vascular seed forming plants
b. vascular spore forming plants
c. non-vascular seed forming plants
d. non-vascular spore forming plants

Answer - B. Vascular Spore Forming Plants. (Confidently Correct)

Reasoning - Ferns, Whisk Ferns and Lycopods are Vascular Plants. Now when we rule out C & D gives us two choices. Ferns, Whisk Ferns and lycopods contain Vascular tissues but do not produce seeds so they are use haploid/unicellular spores instead of seeds for the plants reproduction.

The category is the thing that is most simmilar throughout a period