Agar Is an Excellent Solidifying Agent for Microbiological Media Because $\circ$

Agar is an excellent solidifying agent for microbiological media because

A) it is not degraded by most microorganisms.
B) solid agar remains solid until the temperature is raised to 90 ^$\circ$ C,and liquid agar remains liquid if the temperature is lowered to 45 ^$\circ$ C.
C) it is not degraded by most microorganisms and solid agar remains solid until the temperature is raised to 90 ^$\circ$ C,and liquid agar remains liquid if the temperature is lowered to 45 ^$\circ$ C are correct.
D) agar provides an excellent source of nutrition for a variety of different microorganisms.