Given phrases that describe the relationship between two words/phrases as options, extract the word/phrase pair and the corresponding lexical relationship between them from the input text. The output format should be "relation1: word1, word2; relation2: word3, word4". Options: 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.

Walgreen is part of Walgreens Boots Alliance Inc, and this year sold a majority stake in Trinity's parent Walgreens Infusion Services to private equity firm Madison Dearborn Partners.

Answer: parent_organization: Walgreens, Walgreens Boots Alliance