Which of the following is pyrogallol?

An organic compound $C_6H_7N$ on reaction with $NaNO_2 / HCl$ at $273-278 \ K$ followed by warming with water gives $B$. $B$ reacts with concentrated $HNO_3$ to give $C$. What is $C$?

Which of the following is $\underline{\text{NOT}}$ a dihydric phenol?

What are $X$ and $Y$ in the following reactions?

Major product of reaction :

Which product is obtained when chlorobenzene is reacted with $6-8\%$ aqueous $NaOH$ at $633\,K$ temperature and $300\,bar$ pressure in the presence of an acid catalyst?