Compounds $A$ and $B$,both were treated with $NaOH$,producing a single compound $C$. Identify compound $C$.

Identify the reagent used in the following conversion.

Ethyl acetate reacts with $CH_3MgBr$ to form

$C_6H_5-CO-CHO$ $\xrightarrow{conc. OH^-} (A)$ $\xrightarrow{H_3O^+} (B)$ $\xrightarrow[2. NaOH/CaO/\Delta]{1. KMnO_4} (C)$
Product $(C)$ is:

Compound $P$ $(C_{8}H_{8}O)$ gives a red-orange precipitate with $2,4-DNP$ reagent and it does not reduce Fehling's reagent. On drastic oxidation with chromic acid,$P$ gives an aromatic product $Q$ that produces effervescence on treating with aqueous $NaHCO_{3}$. Compound $P$ and $Q$,respectively,are:

Which of the following reagents converts phenyl methyl ketone into ethylbenzene?