下述四种生物构成的生态系统中，哪种营养结构的生态系统最稳定（ ）
A <img src="https://www.beizhujiaoyu.com/uploads/202208/20191015205229_6332.jpg" alt="" /> B 甲→乙→丙→丁 C <img src="https://www.beizhujiaoyu.com/uploads/202208/20191015205243_0081.jpg" alt="" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/20191015205255_2736.jpg" alt="" />
