The alcohol shown is oxidised with PCC or with Jones reagent, and the product is then treated with $\mathrm{NaBH}{}_4$ and $\mathrm{CeCl}{}_3$ in methanol. Select ALL correct statements.

1. APCC gives the conjugated enone.
2. BJones reagent also gives the conjugated enone, with the C=C bond left intact.
3. CJones reagent cleaves the ring to give a dicarboxylic acid.
4. DThe $\mathrm{NaBH}{}_4$ / $\mathrm{CeCl}{}_3$ step converts the enone back into the starting alcohol (as a racemate).