An organic compound, butane-1,3-diol, is heated under reflux with an excess of acidified potassium dichromate(VI). Which of the following represents the major organic product of this reaction?
CH3CH(OH)CH2COOH\text{CH}_3\text{CH(OH)CH}_2\text{COOH}CH3CH(OH)CH2COOH
CH3COCH2CHO\text{CH}_3\text{COCH}_2\text{CHO}CH3COCH2CHO
CH3COCH2COOH\text{CH}_3\text{COCH}_2\text{COOH}CH3COCH2COOH
HOOCCH2CH2COOH\text{HOOCCH}_2\text{CH}_2\text{COOH}HOOCCH2CH2COOH