Utilize the input text as a context reference, choose the right relationship between Freddie Mac and mortgage loan from the options. 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.

Freddie Mac is guaranteeing four classes of senior securities issued by a third party trust, the FRESB 2015-SB2 Mortgage Trust, and is acting as mortgage loan seller and master servicer.

Answer: product_or_material_produced