$1,1$-dichloropropane undergoes reaction with aqueous sodium hydroxide through a sequence of steps to form propanal. $\text{CH}_3\text{CH}_2\text{CHCl}_2 \xrightarrow{\text{NaOH(aq)}} \text{CH}_3\text{CH}_2\text{CHO}$ What term is used to describe the initial step of this reaction?
- Aaddition
- Belimination
- Coxidation
- Dsubstitution