Task: Question Understanding
Input (English): Question: Which pair of items will repel each other? (A) a positively-charged wool sock and a neutral plastic bag (B) a neutral cotton sweater and a negatively-charged plastic pellet (C) a negatively-charged balloon and a positively-charged piece of paper (D) a negatively-charged plastic strip and a negatively-charged piece of cloth?
Output (English): items, repel