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.

Glencore boss Ivan Glasenberg remains an undisputed billionaire, but the value of his stake has dropped by some 70 per cent.

Answer: chief_executive_officer: Glencore, Ivan Glasenberg; owned_by: Glencore, Ivan Glasenberg; owner_of: Ivan Glasenberg, Glencore