Answer:C.
Step-by-step explanation:
The main reason for the size difference between a moss plant and vascular plants is that vascular plants can transport water in a tube structure called xylem and phloem.
Vascular plants contains tissues that makes up their vascular bundles.
The xylem is used to transport water in plants.
Phloem is used to transport food in plants.
Vascular plants differs from non-plants by possessing this structure.
As the grow they add up more these.
this is an evolutionary edge over the non-vascular plants.