question: cow:milk
choices.label: A B C D
choices.text: clam:pearl bird:nest crab:bee pig:pork
explanation: "milk" can be produced by a "cow". "pearls" can be produced by "clams". "nest" cannot be produced by "birds", and "birds" produce bird eggs. both "crabs" and "bees" belong to animals, and "crabs" cannot be produced by "bees". "pork" is a part of "pig", and "pork" cannot be produced by "pig".
relation: cow milk R3.10
relation: clam pearl R3.10
relation: crab bee R2.4
relation: pig pork R2.3