I believe that the mystery organism is most likely a plant and not an alga if it is surrounded by a cuticle. Thus the answer is B.
Alga and plats are similar in that they can produce their won food from nutrients and sunlight by a process called photosynthesis. The main difference is in their complexity, such that algae are simple organisms, sometimes unicellular, and even the largest types are relatively simple in structure. Green algae does not contain cuticle.
