The Lion and the BullA Lion prowled about in a pasture where four bulls were grazing. He tried many times to capture them, but each time he failed. Whenever he came near, the four bulls turned and formed a ring, so that no matter which way the lion approached, he was met by their horns.One day, however, the bulls had a quarrel and would not speak to one another. Each went alone to a separate part of the pasture to graze. This was the moment the lion had been waiting for. One by one he attacked the bulls and made an end of them.Well-fed and contented, the lion thought, "Those beasts would still be grazing had they remembered:"United we stand; divided we fall."The lion could not catch the bulls because the bulls _______.

• A. were united
• B. ran very fast
• C. were very brave
• D. none of the above