In which conversion does an electrophile attack the organic reactant?
CH3CH2CH2Br⟶CH3CH2CH2OH\text{CH}_3\text{CH}_2\text{CH}_2\text{Br} \longrightarrow \text{CH}_3\text{CH}_2\text{CH}_2\text{OH}CH3CH2CH2Br⟶CH3CH2CH2OH
CH3CH2CHO⟶CH3CH2CH(OH)CN\text{CH}_3\text{CH}_2\text{CHO} \longrightarrow \text{CH}_3\text{CH}_2\text{CH(OH)CN}CH3CH2CHO⟶CH3CH2CH(OH)CN
CH3CH=CH2⟶CH3CHBrCH3\text{CH}_3\text{CH}=\text{CH}_2 \longrightarrow \text{CH}_3\text{CHBrCH}_3CH3CH=CH2⟶CH3CHBrCH3
CH3CH2CH3⟶CH3CH2CH2Cl\text{CH}_3\text{CH}_2\text{CH}_3 \longrightarrow \text{CH}_3\text{CH}_2\text{CH}_2\text{Cl}CH3CH2CH3⟶CH3CH2CH2Cl