Which compound contains a bond angle of approximately 120∘120^\circ120∘?
CH3CH2CH2CH2OH\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{OH}CH3CH2CH2CH2OH
CH3CH2COCH3\text{CH}_3\text{CH}_2\text{COCH}_3CH3CH2COCH3
CH3CH2CH2CH2NH2\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{NH}_2CH3CH2CH2CH2NH2
CH3CH2CH2CN\text{CH}_3\text{CH}_2\text{CH}_2\text{CN}CH3CH2CH2CN