单选题 It is ______ that makes the female horse to bend down and lick its newborn foal.
【正确答案】 D
【答案解析】[解析] 名词词义辨析。impulse“推动，冲动”；inspiration“灵感，启发”；incentive“动机，刺激”；instinct“本能，直觉”。根据句中to bend down and lick its newborn foal应该是一种本能。故答案为D。