The chlorophyta are important for providing oxygen to the atmosphere for depositing diatomic residues as a source of iodine

The chlorophyta are important FOR PROVIDING OXYGEN TO THE ATMOSPHERE.
Chlorophyta refers to the division of lower plants, which is made up of green algae. The plants are aquatic and they found majorly in fresh water and marine habitats, although some are found living on land. Chlorophyta serve as an important source of food to marine organisms and they play a very significant role in contributing to the world's supply of oxygen through the process of photosynthesis.

Your answer is b. codominant