In the following sequence of reactions, the alkene affords the compound 'B'
CH3CH=CHCH3 $\xrightarrow{O_3} \text{A} \underset{Zn}{\xrightarrow{H_2O}} \text{B}$
The compound B is
CH3COCH3
CH3CH2CHO
CH3CHO
CH3CH2COCH3
In the following sequence of reactions, the alkene affords the compound 'B'
CH3CH=CHCH3 $\xrightarrow{O_3} \text{A} \underset{Zn}{\xrightarrow{H_2O}} \text{B}$
The compound B is