What is the relationship between Ralph Norris and Commonwealth Bank 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.

Under former CEO Ralph Norris – a former chief information officer before he rose to lead Australia's biggest bank – Commonwealth Bank of Australia spent billions of dollars upgrading its core systems.

Answer: employer