Which compound is formed from 2-chlorobutane in a nucleophilic substitution reaction?
CH3CH(NH2)CH2CH3\text{CH}_3\text{CH}(\text{NH}_2)\text{CH}_2\text{CH}_3CH3CH(NH2)CH2CH3
CH3CH2CH2CH2NH2\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{NH}_2CH3CH2CH2CH2NH2
CH3CH=CHCH3\text{CH}_3\text{CH}=\text{CHCH}_3CH3CH=CHCH3
CH3CH(CN)CH3\text{CH}_3\text{CH}(\text{CN})\text{CH}_3CH3CH(CN)CH3