Explanation:

- Option 1: António Guterres

- He is the Secretary-General of the United Nations, not NATO.

- Option 2: Jens Stoltenberg

- He is the Secretary General of NATO since 2014.

- Former Prime Minister of Norway.

- Option 3: Admiral Rob Bauer

- Chairman of the NATO Military Committee.

- He holds a military leadership role, not the political Secretary General position.

- Option 4: Stuart Peach

- Former Chairman of the NATO Military Committee.

- Currently serves as the UK Special Envoy to the Western Balkans.

- Option 5: Gladwyn Jebb

- He was the acting Secretary-General of the United Nations in the 1940s.

- Not associated with NATO leadership.