Which one is the most acidic compound?

Which of the following is the strongest acid?

Phenol gives characteristic colouration with

Write the Friedel-Crafts reaction of anisole.

What will be the major product when $m$-cresol is reacted with propargyl bromide $(HC \equiv C-CH_2Br)$ in the presence of $K_2CO_3$ in acetone?

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 $3.$