Answer:
Tracheids, sieve-tube cells, vessel elements, and companion cells are all components of the Complex Permanent Tissue
Explanation:
Complex Permanent Tissue consists of Xylem and Phloem :
Xylem consists Tracheids and vessel element
Phloem consists of sieve-tube cells and companion cells
AS THESE ALL ARE UNDER COMPLEX PERMENANT TISSUE WE CONSIDER IN THIS GROUP
