LONDON (ShareCast) - Premier Oil (LSE: PMO.L - news ) rallied after Jefferies upgraded the stock to 'buy' from 'hold' and raised the price target to 185p from 170p, on the basis of "continued operational delivery in 2H15".
Analyze the relationship between 'Premier Oil' and 'LONDON' within the context of the input sentence.
Options: stock exchange, headquarters location, creator, distribution format