These photosynthetic protists produce one third of the Earth’s oxygen that is generated through photosynthesis. A) algae
B) moss
C) paramecia
D) protozoans

A

Explanation:

this is because these photosynthetic protists have chlororphyll which is capable to make their own food materials through photosynthesis

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).