已知数字信号X和数字信号Y的波形如图，则数字信号<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/23819667_0.png">的波形为（　　）。<br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/23819667_0_1.png">