Cumene is manufactured from benzene and propene, and then converted into phenol by the cumene process. Select the correct statement(s).

1. An-Propylbenzene is the main product of the alkylation step.
2. BThe alkylating electrophile in the first step is the isopropyl (propan-2-yl) carbocation.
3. CPropanone is obtained as a co-product when the hydroperoxide is treated with dilute acid.
4. DCumene is oxidised by air to cumene hydroperoxide, which is an intermediate.