Which of the following will show the haloform reaction?

The reaction shown in the image is:

Which of the following reagents will convert isobutyraldehyde to the corresponding acid?

$I. HNO_3$	$II. NH_2NH_2 / OH^-$
$III. 2[Ag(NH_3)_2]^+$	$IV. NaOH$

$CH_3CHO + HCN$ $\xrightarrow{\text{H}^+} CH_3CH(OH)CN$ $\xrightarrow{\text{H}_3\text{O}^+} CH_3CH(OH)COOH$. In the above reaction,a chiral center is generated. What will be the nature of the resulting acid?

$3$-hydroxybutanal is formed when $(X)$ reacts with $(Y)$ in a dilute $(Z)$ solution. What are $X, Y$ and $Z$?

The general name of the compound formed by the reaction between aldehyde and alcohol is