What is the relationship between Spreadtrum and Tsinghua Unigroup in the context of the input sentence. Choose an answer from: 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.

Intel Corp. bought a 20% stake in Tsinghua Unigroup last year for $1.5 billion.Tsinghua Unigroup, which was founded in 1988 by China’s elite Tsinghua University, became China’s largest chip design firm in 2013 after acquiring two of the country’s largest mobile-chip firms, Spreadtrum Communications and RDA Microelectronics.Micron, based in Boise, Idaho, is the last remaining U.S. maker of the widely used chips known as dynamic random access memory, or DRAMs.

Answer: parent_organization