Which of the following compounds will most easily be attacked by an electrophile?

Given below are two statements:
Statement $I$: Phenol on treatment with $CHCl_3 / aq. KOH$ under refluxing condition, followed by acidification produces $p$-hydroxybenzaldehyde as the major product and $o$-hydroxybenzaldehyde as the minor product.
Statement $II$: The mixture of $p$-hydroxybenzaldehyde and $o$-hydroxybenzaldehyde can be easily separated through steam distillation.
In the light of the above statements, choose the correct answer from the options given below:

The gases evolved in reactions $(I)$ and $(II)$ are.......

Which of the following substituted phenols is the strongest acid?

Which of the following produces violet colour with $FeCl_3$ solution?

Which of the following is a trihydric phenol?