Acetoacetic ester behaves as

Consider the following reaction sequence:
$(CH_3)_2C=CH_2 \xrightarrow[\text{(2) } Zn/H_2O]{\text{(1) } O_3} X + Y$
$X + Y \xrightarrow[\text{(2) } \Delta]{\text{(1) dil. } NaOH} Z$
The $IUPAC$ name of '$Z$' is

Identify the product $Y$ in the sequence: $CH_3-CHO + CH_3-MgI$ $\xrightarrow{\text{Ether}} X$ $\xrightarrow{H_2O/H^{+}} Y$

Given below are two statements:
Statement $I$ : Acidity of $\alpha$-hydrogens of aldehydes and ketones is responsible for Aldol reaction.
Statement $II$ : Reaction between benzaldehyde and ethanal will $NOT$ give Cross-$Aldol$ product.
In the light of above statements,choose the most appropriate answer from the options given below.

Statement $I$: Aldehyde on reaction with $HCN$ gives Cyanohydrin.
Statement $II$: Cyanohydrin is a compound which consists of hydroxy and cyano groups on the same carbon.
Choose the correct answer from the following with reference to above statements.

Comment on the stereochemistry of the products for the following reaction:
$3$-methylpentan-$2$-one + $CH_3MgBr$ followed by $NH_4Cl$ workup.