Nic Walker Share on twitter by Sue Mitchell South African retailer Woolworths Holdings has turned to former Westpac chief executive Gail Kelly to help transform itself into a leading southern hemisphere retailer after last year's $2.1 billion acquisition of David Jones.
Take context from the input text and decide on the accurate relationship between 'Gail Kelly' and 'Westpac' from the options provided.
Options: legal form, subsidiary, employer, platform