Compared with 1-chloropropane under identical conditions ($\mathrm{NaI}$, dry acetone), the compound shown reacts:

1. Amuch faster, because the transition state is stabilised by overlap with the adjacent pi bond
2. Bmuch slower, because the double bond withdraws electrons by resonance from the C-Cl carbon
3. Cat the same rate, because both are primary halides
4. Dnot at all, because the carbon bearing chlorine is sp2 hybridised