What is the relationship between Premier Oil and London in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

6,093.00p -0.26% London Stock Exchange Group (LSE) 2,573.00p -0.23% FTSE 250 - Risers Greggs (GRG) 1,285.00p +8.53% Rathbone Brothers (LSE: RAT.L - news ) (RAT) 2,277.00p +7.71% Man Group (LSE: EMG.L - news ) (EMG) 162.40p +7.55% Foxtons Group (LSE: FOXT.L - news ) (FOXT) 239.40p +7.35% Renishaw (RSW) 2,100.00p +6.92% Tate & Lyle (LSE: TATE.L - news ) (TATE) 544.50p +6.56% Premier Oil (LSE: PMO.L - news ) (PMO) 135.40p +5.78% Rightmove (RMV) 3,574.00p +5.43% Ophir Energy (Other OTC: OPGYF - news ) (OPHR) 110.40p +5.34% Evraz (EVR) 101.50p +4.96% FTSE 250 - Fallers Premier Farnell (LSE: PFL.L - news ) (PFL) 140.00p -15.97% Lonmin (LMI) 55.60p -5.92% Pets at Home Group (PETS) 274.10p -4.83% Lancashire Holdings Limited (Other OTC: LCSHF - news ) (LRE) 644.00p -4.02% Ladbrokes (Amsterdam: LB6.AS - news ) (LAD) 114.10p -2.81% Allied Minds (Other OTC: ALLWF - news ) (ALM) 469.30p -2.76% Redefine International (RDI) 52.10p -2.53% Fisher (James) & Sons (FSJ) 1,125.00p -2.51% Polymetal International (Other OTC: AUCOY - news ) (POLY) 447.90p -2.14% Brown (N.) Group (BWNG) 321.90p -1.71%

Answer: headquarters_location