Refer to the input text as context and select the correct relationship between 'Telstra' and 'David Thodey' from the available options.
Options: distributed by, brand, operator, chief executive officer

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.
chief executive officer