Phenol is

Due to resonance,the oxygen atom of the $-OH$ group in phenol:

Which of the following is the most acidic compound?

Which one of the following statements is not correct?

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 main product of the following reaction will be: