Refer to the input text as context and select the correct relationship between 'Premier Oil' and 'LONDON' from the available options.
Options: stock exchange, headquarters location, distribution format, creator

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".
headquarters location