Why Are Definite and Distinct Root and Shoot Systems Uncommon

Multiple Choice

Why are definite and distinct root and shoot systems uncommon in aquatic algae,but present in most land plants?

A) The earliest plants had a sprawling growth form.
B) Aquatic algae cannot grow more than a couple of centimeters in height.
C) Land plants need to be anchored to the ground,whereas aquatic algae do not.
D) Land plants cannot exchange gases with their environment as easily as aquatic algae.
E) Aquatic algae obtain most inputs for photosynthesis directly from the water that surrounds them.