Answer: A (Mutualism)
Explanation:
The relationship between termites and cellulose digestive microorganisms is Mutualism. This is because Termites feed on cellulose, which they get from feeding on dry woods.
Termites themselves can not degrade cellulose but the depend on microorganisms in their guts. These microorganisms releases enzymes that solely degrade cellulose.
The symbiotic relationship between termites and cellulose digestive microorganisms is Mutualism because they both depend on each other for survival. Microorganisms would not survive outside of the termite, and the termite would not be able to degrade food if it didn't have cellulose digestive microorganisms to aid in digestion.