Which of the following is a trihydric phenol?

Phenol $\xrightarrow[{{H^ + }}]{{CHCl_3/NaOH}}$ Salicylaldehyde. The above reaction is known as:

When phenol is reacted with $CHCl_3$ and $NaOH$ followed by acidification,salicylaldehyde is obtained. Which of the following species are involved in the above mentioned reaction as intermediates?

Benzoylation of phenol with benzoyl chloride in the presence of dilute $NaOH$ gives phenyl benzoate. This reaction is an example of

Match the following reactions of phenol with their products:

Benzoic acid gives benzene on being heated with $X$ and phenol gives benzene on being heated with $Y$. Therefore $X$ and $Y$ are respectively