The growth of algae in ocean water is limited by their need for
a.
warm ocean currents.
b.
carbon dioxide and sunlight.
c.
dissolved oxygen.
d.
low salinity.

b. carbon dioxide and sunlight.

Explanation:

plants usually undergo photosynthesis to produce food or nutrient for them self. Algae as a plant requires carbon dioxide and water in the presence of sunlight to photosynthesize.

The amount of sunlight that penetrate the depth of ocean water is limited, The limited amount of this sunlight denies plants that rely on them for photosynthesis to end up dead. The carbon dioxide availability in the ocaen is also limited because most times when carbon dioxide dissolve in ocean water it tends to form acidic water.

Generally, The growth of algae in the ocean water is limited by their need of  carbon dioxide and sunlight for photosynthesis.  

The answer is c

10.4 percent

options a, b, d and e don't match the calculations at all.