Which compound reacts with Tollens' reagent to form a silver mirror but does not give a brick-red precipitate with Fehling's solution?
C6H5CHO\text{C}_6\text{H}_5\text{CHO}C6H5CHO
CH3CH2CHO\text{CH}_3\text{CH}_2\text{CHO}CH3CH2CHO
C6H5COCH3\text{C}_6\text{H}_5\text{COCH}_3C6H5COCH3
CH3CH(OH)CH3\text{CH}_3\text{CH(OH)CH}_3CH3CH(OH)CH3