Which of the following reactions can be used to convert an unsaturated ketone into an unsaturated hydrocarbon?

Match the reactions in Column-$I$ with their products in Column-$II$.
| Column-$I$ (Reagents) | Column-$II$ (Product) |
| :--- | :--- |
| $(A) \ CH_3CHO + 2C_2H_5OH \xrightarrow{HCl_{(g)}} $ | $(i) \ (CH_3)_2C(OCH_2)_2$ |
| $(B) \ CH_3COCH_3 + CH_2OH-CH_2OH \xrightarrow{HCl_{(g)}} $ | $(ii) \ CH_3CH(OH)CN$ |
| $(C) \ CH_3CHO + HCN$ $\xrightarrow{OH^-}$ $\xrightarrow{H_3O^+}$ | $(iii) \ CH_3CH(OC_2H_5)_2$ |
| $(D) \ CH_3CHO + HCN \xrightarrow{OH^-} $ | $(iv) \ CH_3CH(OH)COOH$ |

How can propan$-2-$one be converted to tertiary butyl alcohol?

Arrange the following compounds in order of decreasing reactivity for nucleophilic addition reaction:
$(I)$ $CH_3COCH_2Cl$
$(II)$ $ClCH_2CHO$
$(III)$ $HCHO$
$(IV)$ $CH_3COCH_3$

Iodoform test is not given by

Benzaldehyde can be converted to benzonitrile by treatment with