The Major Photosynthesizing Organisms in the Ocean Are Phytoplankton and Algae.These

Multiple Choice

The major photosynthesizing organisms in the ocean are phytoplankton and algae.These organisms obtain most of the CO₂ necessary for photosynthesis from which source?

A) They take it directly from the atmosphere.
B) They use CO₂ dissolved in ocean water.
C) They use CO₂ respired by surrounding organisms.
D) They break down organic molecules in the ocean.
E) They break down carbonate from ocean sediments.