Halogenoalkanes take part in a variety of nucleophilic substitution reactions. Which reaction occurs only through an S$_\text{N}1$ mechanism?
- ACH$_3$CH$_2$Br $+$ NH$_3$
- BCH$_3$CH$_2$CH$_2$I $+$ OH$^-$
- CCH$_3$CHBrCH$_3$ $+$ NH$_3$
- D(CH$_3$)$_3$CI $+$ OH$^-$