Answer

3. He was given carte blanche to teach the new staff using whatever methods he liked.

🙋‍♂️ carte blanche

Meaning

If you give someone carte blanche, you give them freedom to do whatever they want in a situation.

For example

• The boss has given us carte blanche to redecorate the offices.
• The president gave his generals carte blanche to fight the war however they wished.

Origin: Originally borrowed from French. A literal translation would be "white (or blank) paper".