In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Context: Shamrock briefly feuded with Jeff Jarrett before beginning a rivalry with martial artist Link Information: Blackman opened a self-defense school in Harrisburg, Pennsylvania called "BlackmanMMA" in mid-2003, teaching jujitsu Question: What martial arts does the man who Ken had a rivalry with after Jeff Jarrett participate in?
Answer: jujitsu