Question

Rank the following sets of substituents in order of priority according to the sequence . explain your answer
a. ch3, Br, H, I
b.OH, OCH₃, H, CO₂H
c. CH₃, CO₂H , CH₂OH, CHO
d CH₃, CH=CH₂, CH2CH₃, CH(CH3)₂

in part d the priority was for the double bond however in part c it wasn't !! whyy??

or instroctor told us CH₂OH is less priority than CHO!!

my test is tomorrow i need hellp >>>