What is the relationship between Intertek 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.

Market Movers techMARK 3,192.58 0.00% FTSE 100 6,775.08 -0.31% FTSE 250 17,755.91 -0.05% FTSE 100 - Risers easyJet (EZJ) 1,698.00p +1.80% International Consolidated Airlines Group SA (CDI) (IAG) 567.00p +1.61% TUI AG Reg Shs (DI (KSE: 003160.KS - news ) ) (TUI (LSE: TUI.L - news ) ) 1,102.00p +1.47% Sports Direct International (Other OTC: SDIPF - news ) (SPD) 747.00p +1.43% Hikma Pharmaceuticals (LSE: HIK.L - news ) (HIK) 2,128.00p +1.29% BT Group (LSE: BT-A.L - news ) (BT.A) 477.90p +1.19% Intertek Group (Other OTC: IKTSF - news ) (ITRK) 2,435.00p +1.08% Lloyds Banking Group (LLOY) 87.40p +1.03% London Stock Exchange Group (LSE) 2,699.00p +1.01% Pearson (PSON) 1,275.00p +0.95% FTSE 100 - Fallers Royal Mail (LSE: RMG.L - news ) (RMG) 508.50p -3.51% Randgold Resources Ltd. (RRS) 4,004.00p -2.01% Fresnillo (FRES) 658.00p -1.57% Anglo American (LSE: AAL.L - news ) (AAL) 877.40p -1.45% Royal Dutch Shell (Xetra: R6C1.DE - news ) 'B' (RDSB) 1,829.50p -1.40% Persimmon (PSN) 1,978.00p -1.40% Barratt Developments (LSE: BDEV.L - news ) (BDEV) 635.50p -1.32% Dixons Carphone (LSE: DC.L - news ) (DC.)

Answer: headquarters_location