Refer to the input text as context and select the correct relationship between 'Thomson Reuters' and 'software' from the available options.
Options: stock exchange, chairperson, employer, product/material produced

Symantec Corp, the antivirus and security software maker best known for its Norton antivirus software, is expected to report first-quarter earnings slightly below analysts' expectations on Tuesday, according to Thomson Reuters I/B/E/S.
product/material produced