I believe the answer is C. They are a type of jelly fish.
The answer to this is : B, Their roots.
That's true because the basic functions of a multi-cellular plant occur in the cell and like any other cell, unicellular alga are also cells thus basic functions such as respiration, excretion, growth occur in both multicellular organisms as well as unicellular organisms
Answer is a. neolithic where they use wild and domesticated crops and domesticated animals
No u dont because earth gravitational pull is stronger also it is a scientific law