For phenol,which of the following statements is correct?

Phenol condenses with phthalic anhydride in the presence of conc. $H_2SO_4$ to form:

The Reimer-Tiemann reaction introduces an aldehyde group onto the aromatic ring of phenol,ortho to the hydroxyl group. This reaction involves electrophilic aromatic substitution. This is a general method for the synthesis of substituted salicylaldehydes as depicted below.
$1.$ Which one of the following reagents is used in the above reaction?
$A.$ aq. $NaOH + CH_3Cl$
$B.$ aq. $NaOH + CH_2Cl_2$
$C.$ aq. $NaOH + CHCl_3$
$D.$ aq. $NaOH + CCl_4$
$2.$ The electrophile in this reaction is
$A.$ $:CHCl$
$B.$ $^{+}CHCl_2$
$C.$ $:CCl_2$
$D.$ $CCl_3^{-}$
$3.$ The structure of the intermediate $I$ is
(See provided image for structures $A$,$B$,$C$,$D$)
Give the answer for questions $1, 2$ and $3.$

The reaction of phenol with chloroform in the presence of dilute sodium hydroxide introduces which one of the following functional groups?

Which of the following is the weakest acid?

When a mixture of vapours of phenol and hydrogen is passed over nickel catalyst at $433 \ K$,the product obtained is