Which statement about the pentahalides of group 15 is correct?

1. A$\mathrm{PCl}{}_5$, $\mathrm{AsCl}{}_5$, $\mathrm{SbCl}{}_5$ and $\mathrm{BiCl}{}_5$ are all stable at room temperature
2. B$\mathrm{BiF}{}_5$ is known, while $\mathrm{BiCl}{}_5$ is not, because the Bi(V) state is destabilised by the inert pair effect and only fluorine can stabilise it
3. C$\mathrm{BiF}{}_5$ is not known because fluorine is too small
4. DAll pentahalides of bismuth exist, as bismuth has five valence electrons