According to Cahn- lngold- Prelog sequence rules, the correct order of priority for the given groups is :

Question

\[\begin {array} {1 1} (1)\;COOH > - CH_2OH > -OH < - CHO \\ (2)\;-COOH > - CHO > - CH_2OH > - OH \\ (3)\;-OH > -CH_2 OH > - CHO > -COOH \\  (4)\;-OH > - COOH > - CHO > -CH_2OH \end {array}\]