7. A judicial case. In the country of knights and liars, a crime was committed. Three residents of the country were brought to court: $\mathcal{A}$, $B$, and $C$. When the judge asked a question, $\mathcal{A}$ answered inaudibly. When the judge asked the two remaining individuals again, $B$ said that $\mathcal{A}$ claims he is a knight, and $C$ said that $\mathcal{A}$ called himself a liar. Who are $B$ and $C$?
7. Obviously, $\mathcal{A}$ said that he is a knight, since $\mathcal{A}$ is a resident of the country. Further, from the condition of the problem, it is clear that $B$ is a knight, and $C$ is a liar.