$A$ and $B$ in the following reactions are

Which of the following arrangements with respect to their reactivity in nucleophilic addition reaction is correct?

The above compounds can be differentiated by the following reagent:

The given reaction is an example of an intramolecular aldol condensation. Identify the product $(A)$ formed in the reaction:
$1,5-\text{cyclooctanedione} \xrightarrow{H_2SO_4, H_2O} (A)$

The major products $Y$ and $Z$ in the following reactions are

Phenylmagnesium bromide,upon reaction with a compound $X$ followed by treatment with acid,gives benzyl alcohol. The compound $X$ is