The structure of intermediate $A$ in the following reaction is

The acidic nature of phenol is due to which of the following?

What will be the product of the reaction with $HBr$?

Phenols are more acidic than alcohols because

The order of acidic strength of $X, Y$ and $Z$ is:
Phenol reacts with dilute $HNO_3$ to form $X$ ($o$-nitrophenol) and $Y$ ($p$-nitrophenol). Phenol reacts with concentrated $HNO_3$ and $H_2SO_4$ to form $Z$ ($2,4,6$-trinitrophenol or picric acid).

Which of the following is the major product,when $p$-cresol is treated with zinc dust?