Select the correct statements about SN2 reactions of cyclic halides.

1. A1-Bromobicyclo[2.2.1]heptane is inert to SN2 because the backside of the C-Br carbon lies inside the cage and is shielded by the skeleton.
2. BBromocyclopropane is far less reactive than bromocyclopentane because the SN2 transition state needs an sp2-like carbon with wide angles, which increases the angle strain in the three-membered ring.
3. CIn a conformationally locked bromocyclohexane, an axial bromine is displaced faster than an otherwise identical equatorial bromine, because the nucleophile then approaches from the less hindered equatorial direction.
4. D1-Bromo-1-methylcyclohexane reacts with $\mathrm{NaI}$ in acetone mainly by SN2 to give 1-iodo-1-methylcyclohexane.