Answer: 1, 3, and 4.
Step-by-step explanation:
Wendi, also known as Yang Jian, wanted to bring China together, so he did some important things. First, he set up a strong central government to make sure everything ran smoothly. Then, he started building the Grand Canal, which was like a superhighway connecting different parts of China, helping trade and communication. Lastly, he made sure everyone used the same kind of money, making things more stable economically. Basically, he wanted everyone to work together better, and these moves helped make China more united during the Sui Dynasty.