Which Group of Plants Has Two Types of Xylem Tubes,each

Question

Which group of plants has two types of xylem tubes,each composed of one cell type,vessel elements?  
A) Gymnosperms
B) Monocots
C) Bulbs
D) Early vascular plants
E) Angiosperms

Accepted Answer

Angiosperms are the group of plants that have two types of xylem tubes, each composed of one cell type - vessel elements. This is one of the distinguishing features of angiosperms compared to gymnosperms and early vascular plants, which only have one type of xylem tube. Monocots and bulbs are types of angiosperms, but this distinction is not relevant to this question.