Answer:
A. The algae are heterotrophs
Explanation:
Algae which are heterotrophic obtain nutrients from complex organic substances. Thus, this type of algae is a consumer. This is in contrast to autotrophs, which form their own organic substances from simple inorganic substances. They produce their own energy
The diammonium phosphate which run off until the lake nourish these algae and make them grow without limit.
The answer you're looking for is B. Sporophyte
