The correct option is
C Algae
Agar- Agar is a jelly ike substance, obtained from algae. Agar forms the supporting structure in the cell walls of certain species of algae, which is released on boiling. These algae are known as agarophytes. Agar can be used as a laxative, an appetite suppressant, a vegetarian substitute for gelatin, a thickener for soups , in fruit preserves and ice creams, as a clarifying agent in brewing,culture media for microbiologial work etc.
Algae is the division of the lower plant which contain chlorophyll in the cell. They are divided broadly as macro- algae ( macroscopic algae ) and micro-algae ( microscopic algae). They have multiple uses.
Option B is correct.