Which of the following compounds will not undergo tautomerism?

Which of the following compounds would undergo aldol condensation,which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction.
$(i)$ Methanal $(ii)$ $2-$Methylpentanal $(iii)$ Benzaldehyde $(iv)$ Benzophenone $(v)$ Cyclohexanone $(vi)$ $1-$Phenylpropanone $(vii)$ Phenylacetaldehyde $(viii)$ Butan$-1-$ol $(ix)$ $2,2-$Dimethylbutanal

Which one of the following on treatment with $50 \% \text{ aq. } NaOH$ yields the corresponding alcohol and salt of carboxylic acid?

The major product of the above reaction is $A$.

The iodoform test can differentiate between:
$A$. Methanol and Ethanol
$B$. $CH_3COOH$ and $CH_3CH_2COOH$
$C$. Cyclohexene and cyclohexanone
$D$. Diethyl ether and Pentan$-3-$one
$E$. Anisole and acetone
Choose the correct answer from the options given below:

Compound $X$ undergoes the following reaction sequence. What is the structure of compound $X$?