Converting 3-bromopropanal to 1-bromopropane is to be done by just reducing the carbonyl group -CHO to the methylene group −CH2−, thereby forming alkanes and reducing aldehydes and ketones. Wolf Kishner reduction reduces aldehydes or ketones into its respective alkanes with the help of hydrazene in KOH. Clemmenson reduction reduces aldehydes or ketones into its respective alkanes with the help of zinc amalgam and conc. HCl. So, both of the reactions can be used.