Encouraging the Growth (Via Nutrient Fertilization)of Photosynthetic Protists in Marine

Encouraging the growth (via nutrient fertilization) of photosynthetic protists in marine environments may help reduce global warming.Why?

A) because photosynthetic protists form the base of many marine food chains
B) because photosynthetic protists fix atmospheric carbon dioxide,decreasing atmospheric CO₂ levels
C) because the increased oxygen consumption by large populations of photosynthetic protists will promote land plants to speed up photosynthesis,thus removing CO₂ from the atmosphere
D) because photosynthetic protists would release a lot of oxygen,and fertilizing them would increase levels of oxygen in the atmosphere