What is the relationship between Barry Rosenstein and Jana Partners 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.

Investing alongside powerful activists like Carl Icahn, Pershing Square’s Bill Ackman, Trian Partners’ Nelson Peltz or Barry Rosenstein of Jana Partners can produce big profits.

Answer: employer