What is the relationship between 'David Thodey' and 'Telstra' in the context of the input sentence.
Options: employer, parent organization, position held, owner of

David Thodey engineered a stunning turnaround at Telstra , extending its dominant position in the mobile sector, negotiating lucrative agreements with the government (twice) over the National Broadband Network, selling off non-core assets and cutting expenses.
employer