In this task, you're given a passage, 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'.
Q: Passage: In July 2011, Ball signed a new three-year contract, which extended his stay at the Pride Park club until at least 2014. Ball scored his first senior goal for the club in a 21 win at home to Bristol City on 10 December 2011. Ball then scored the opening goal of the game against West Ham which was a great curling effort form the edge of the area after being played in by Nathan Tyson, this was the second former England goal keeper (Robert Green) he had scored against after scoring his first goal against David James. Ball scored his 3rd goal for derby, which proved to be the winner against Coventry City, once again this proved to be a goal against an internationally capped goal keeper in Joe Murphy who at the time had been capped twice by the Republic of Ireland. Ball became a regular in the Rams matchday 16 until he picked up an ankle injury in a reserves game against Belper Town on 26 March 2012. Ball returned from injury a 32 reserve win against Sunderland Reserves in the Totesport Cup semi-final game on 19 April 2012, playing the whole 90 minutes in central defence.
Link Information: The following season they finished as runners-up in the Premier Division and were promoted to Division One of the Northern Premier League Question: Which league was Belper Town F.C. playing in when Ball picked up an ankle injury?
A:
Answer: Northern Premier League