Phenol is manufactured from hydrocarbon, Cumene. Cumene is chemically:

The correct option is Isopropyl benzene.

Cumene is the common name for the aromatic hydrocarbon isopropylbenzene.
In its chemical structure, an isopropyl group, which is a three-carbon chain branched at the middle carbon, is attached to a benzene ring.

The chemical formula for cumene is represented as:
$$C_6{H}_{5}CH{\left(C{H}_3\right)}_2$$

In the industrial manufacturing of phenol (known as the cumene process), isopropylbenzene (cumene) is oxidized by air to form cumene hydroperoxide. This intermediate is then treated with a dilute acid to produce phenol and acetone as a valuable by-product.