Zhu Wen, originally a salt smuggler who had served under the rebel Huang, surrendered to Tang forces. By helping to defeat Huang, he was granted a series of rapid military promotions. In 907 the Tang dynasty was ended when Zhu Wen, now a military governor, deposed the last emperor of Tang, Emperor Ai of Tang, and took the throne for himself (known posthumously as Emperor Taizu of Later Liang). He established the Later Liang, which inaugurated the Five Dynasties and Ten Kingdoms period. A year later Zhu Wen had the deposed Emperor Ai poisoned to death.

Answer this question based on the passage: who was the last ruler of the tang dynasty? Okie... think carefully first, then make a decision:
The important part for answering this question is: In 907 the Tang dynasty was ended when Zhu Wen, now a military governor, deposed the last emperor of Tang, Emperor Ai of Tang, and took the throne for himself (known posthumously as Emperor Taizu of Later Liang). So, the answer is Emperor Ai of Tang.