An organic compound $A$,$C_5 H_8 O$,reacts with $H_2 O$,$NH_3$,and $CH_3 COOH$ as shown in the reaction scheme. Identify $A$.

The major product $A$ obtained in the above reaction is:

The most likely protonation site in the following molecule is:

What is the fission of a covalent bond? Explain its types with examples and the main differences.

Different possible thermal decomposition pathways for peroxyesters are shown below. Match each pathway from List-$I$ with an appropriate structure from List-$II$ and select the correct answer using the code given below the lists.
List-$I$:
$P$. Pathway $P$
$Q$. Pathway $Q$
$R$. Pathway $R$
$S$. Pathway $S$
List-$II$:
$1$. $C_6H_5CH_2CO_3CH_3$
$2$. $C_6H_5CO_3CH_3$
$3$. $C_6H_5CH_2CO_3C(CH_3)_2CH_2C_6H_5$
$4$. $C_6H_5CO_3C(CH_3)_2C_6H_5$
Codes:
$P \quad Q \quad R \quad S$
$A. 1 \quad 3 \quad 4 \quad 2$
$B. 2 \quad 4 \quad 3 \quad 1$
$C. 4 \quad 1 \quad 2 \quad 3$
$D. 3 \quad 2 \quad 1 \quad 4$

Which statement from the following is correct for homolytic fission?