Which of the following must unicellular organisms do to maintain homeostasis?
a. use chemical signals to communicate between its cells
b. change food or sunlight into useful energy
c. specialize cells to perform specific functions
d. organize cells into tissues

I got c because all living cells exhibit the process which is homeostasis 

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.