Utilize the input text as a context reference, choose the right relationship between Western Digital and SanDisk 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.
Text: Hard-disk drive maker Western Digital Corp will buy SanDisk Corp in a $19 billion that will greatly increase its ability to make flash memory storage chips used in smartphones and tablets.
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