Utilize the input text as a context reference, choose the right relationship between Ruth Porat and chief financial officer 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.

Ruth Porat left her post as chief financial officer of Morgan Stanley this year to become Google's CFO.

Answer: position_held