An organic compound, ${\mathrm{C}}_3{\mathrm{H}}_6\mathrm{O}$ gives a positive iodoform test. On saturation with dilute $\mathrm{HCl}$, it gives compound$\text{'}\mathrm{X}\text{'}$having molecular formula ${\mathrm{C}}_9{\mathrm{H}}_{14}\mathrm{O}$. $\mathrm{X}$ is

$\mathrm{Ethane} \mathrm{nitrile} \stackrel{\mathrm{Na}/\mathrm{EtOH}}{\to }\mathrm{A}\stackrel{{\mathrm{HNO}}_2}{\to }\mathrm{B}\stackrel{\mathrm{PCC}}{\to }\mathrm{C}$

The product $\mathrm{C}$ in the above series is 

What are the correct statements about the products in the above sequence of reactions?

$\text{(a) B}$ can give a positive iodoform test.

$\left(\mathrm{b}\right) \mathrm{C}$ can exist in the form of enantiomers

$\left(\mathrm{c}\right) \mathrm{C}$ on heating gives a diastereomeric mixture.

$\left(\mathrm{d}\right) \mathrm{B}$ on oxidation gives an unsymmetrical ketone.

$\left(\mathrm{e}\right) \mathrm{B}$ gives a red colour in Victor Meyer test.

The reaction of $\mathrm{R}-2-\mathrm{hydroxy} \mathrm{propanal}$ with $\mathrm{HCN}$ occurs in basic medium. Among the following statements, which ones are correct?

$\left(\mathrm{a}\right)$ The product formed is chiral and exist as a racemic mixture.

$\left(\mathrm{b}\right)$ Racemisation occurs at ${\mathrm{C}}_1$ of reactant as carbonyl group is a planar group.

$\text{(c) }$Product formed exists as diastereomers.

$\left(\mathrm{d}\right)$ Basic medium increase ionization of $\mathrm{HCN}$ and increases ${\mathrm{CN}}^{-}$ ,i.e., the nucleophile.
 

In which one of the following, all the compounds will give positive Tollen's test?

What is the number of aldol reactions that occur in the given transformation?