Which compound does not contain an asymmetric carbon atom?
CH3CH2CH(CH3)CH2CH3\text{CH}_3\text{CH}_2\text{CH}(\text{CH}_3)\text{CH}_2\text{CH}_3CH3CH2CH(CH3)CH2CH3
CH3CH(Cl)CH2CH2CH3\text{CH}_3\text{CH}(\text{Cl})\text{CH}_2\text{CH}_2\text{CH}_3CH3CH(Cl)CH2CH2CH3
CH3CH2CH(NH2)COOH\text{CH}_3\text{CH}_2\text{CH}(\text{NH}_2)\text{COOH}CH3CH2CH(NH2)COOH
CH3CH(OH)CH2CH3\text{CH}_3\text{CH}(\text{OH})\text{CH}_2\text{CH}_3CH3CH(OH)CH2CH3