Task: Question Answering
Input (English): Termites eat wood but cannot digest it. Protozoans live in the termites' stomachs and use enzymes to break down the wood. The digested wood provides nutrition for both the termites and the protozoans. What type of relationship is this?  
 (A) mutualism (B) parasitism (C) predation (D) commensalism
Output (English): A