Knights : x : TRUE wala.
Knaves : y: FALSE wala.
A: “B is x”
Option A :
A is x & B is x?
As A is x: which means he is true → B is x
As B is given/proven to be x → A must be y: CONTRADICTION: HENCE OPTION A IS FALSE
Option B :
A is x & B is y?
As A is x: which means he is true → B is x: CONTRADICTION: HENCE OPTION B is also FALSE
Option C :
A is y & B is y?
A is y → which means A is false → B is y
B is y → which means B is false → A is y
@Deepak Poonia sir : Please confirm this.
It’s correct But making two cases is more efficient. Being efficient is also important.