The product $(C)$ of the given reaction sequence is:

Saponification (basic hydrolysis) of $C_6H_5-CO-^{18}OCH_3$ will yield. [$^{18}O$ = mass $-18$ isotope of oxygen]

An organic acid $P$ $(C_{11}H_{12}O_2)$ can easily be oxidized to a dibasic acid which reacts with ethylene glycol to produce a polymer,dacron. Upon ozonolysis,$P$ gives an aliphatic ketone as one of the products. $P$ undergoes the following reaction sequences to furnish $R$ via $Q$. The compound $P$ also undergoes another set of reactions to produce $S$.
$(1)$ The compound $R$ is
$(2)$ The compound $S$ is
Give the answer for questions $(1)$ and $(2)$.

Which of the following reactions give $RCONH_2$?

Product $(G)$ is

An ester $(A)$ with molecular formula $C_9H_{10}O_2$ is reacted with an excess of $CH_3MgBr$. The resulting product is treated with concentrated $H_2SO_4$ to form an olefin $(B)$. Ozonolysis of $(B)$ yields a ketone with the formula $C_8H_8O$. What is the structure of $(A)$?