$CH_3-CO-CH_3$ $\xrightarrow{NaCN/HCl} A$ $\xrightarrow{H_3O^{+}/\Delta} B$. In the above sequence of reactions,$A$ and $B$ are:

What is the correct order of reactivity of the following compounds towards a Grignard reagent?
$(I)$ $CH_3CHO$
$(II)$ $HCHO$
$(III)$ $CH_3COC_6H_5$

Contents of three bottles were found to react as follows:
$(i)$ Neither with Fehling's solution nor with Tollen's reagent
$(ii)$ Only with Tollen's reagent but not with Fehling's solution
$(iii)$ With both Tollen's reagent and Fehling's solution.
If they contained either ethanal,propanone,or benzaldehyde,which bottle contained which?

Identify the product $A$ in the following reaction:

The product $(B)$ of the reaction is:

Following compounds are given:
$(i) CH_3-CH_2-OH$
$(ii) CH_3-CO-CH_3$
$(iii) CH_3-CH(OH)-CH_3$
$(iv) CH_3-OH$
Which of the above compound$(s)$,on being warmed with iodine solution and $NaOH$,will give iodoform?