Q: In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Question: Were any of the emperors Ji served assassinated? Passage:Jiang Ji (died 18 May 249), courtesy name Zitong, was an official and military general of the state of Cao Wei during the Three Kingdoms period of China. Born in the late Eastern Han dynasty, Jiang Ji started his career as a low-level official in his native Yang Province before becoming a subordinate of Cao Cao, the warlord who controlled the central government towards the end of the Eastern Han dynasty. After the end of the Eastern Han dynasty, he served in the state of Cao Wei through the reigns of the first three emperors – Cao Pi, Cao Rui and Cao Fang – and held various appointments in the military before rising to Grand Commandant, one of the top positions in the central government. During his service in Wei, he was known for being candid in giving advice to the emperor on various issues, including consolidating power, halting labour-intensive construction projects, and officials' abuses of power. In February 249, he joined the regent Sima Yi in staging a successful coup d'état against his co-regent Cao Shuang, but died from illness a few months later.

A:
b