Which among the following compounds has the highest solubility in water?

Consider the following reaction sequence:
$\text{Compound } (x)$ $\xrightarrow[(ii) H_3O^{+}]{(i) CO_2, NaOH, 120^{\circ}C, \text{high pressure}} \text{Compound } (y) \text{ (Major Product)}$
$[76.6\% C, 6.38\% H, \text{vapour density } 47]$
Compound $(y)$ develops a characteristic color with neutral $FeCl_3$ solution.
Identify the $INCORRECT$ statement from the following for the above sequence.

Identify the reactant $x$ in the following chemical reaction:
$Phenol + (x) \xrightarrow[(2) H^+]{(1) NaOH} Salicylaldehyde$

$Acetophenone$ $\xrightarrow{{HCO_3H}} A$ $\xrightarrow{{H_3O^{+}}} B + C$ $\mathop {\xrightarrow{{Phthalic \, Anhydride}}}\limits_{{H^{+}}} $ Indicator $(D)$
$C$ and $D$ are

Arrange the following compounds in increasing order of acidity and provide a suitable explanation: $o-\text{cresol}$,$\text{phenol}$,$o-\text{nitrophenol}$.

What product is formed when phenol reacts with dilute $HNO_3$?