Select the most appropriate meaning of the given proverb.
Just what the doctor ordered
1
Rules change depending on how powerful the person likely to be affected by the rules is
2
People who have long been used to doing things in a particular way will not abandon their habits to learn something new
3
Exactly the thing that is or was needed to help improve something or make one feel better
4
It is hard to achieve something important without causing unpleasant effects