What is the relationship between MasterCard and purchase 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.

SAA Voyager Gold MasterCard credit cardholder Annual Card Fee: USD 25 Voyager Earn Rate– 1 SAA Voyager Mile for USD 4 spend Double Miles on eligible spend for the first month (only provided once per new card account) 10,000 Bonus Miles on 1st SAA ticket purchase (only provided once per new card account) Premium check-in 1 Additional piece of luggage when travelling in business class at 32kgs when travelling on SAA-operated flights 1 Additional piece for economy class at 23kgs when travelling on SAA-operated flights 10% discount on excess luggage rates when paying with the SAA Voyager MasterCard Credit Cards for all SAA-operated flight sectors per ticket, originating from and to Accra

Answer: headquarters_location