Compound $(A)$ with molecular formula $C_{11}H_8O$ does not undergo self-aldol condensation. Upon ozonolysis,it yields $Ph-CHO$ and $2B$,where $B$ on oxidation with $Ag^{+}$ gives oxalic acid. Identify compound $(A)$.

Consider the following reactions:
$A$ $\xrightarrow[(i) CH_3MgBr]{(ii) H_3O^{+}} B$ $\xrightarrow[573 \text{ K}]{Cu} 2\text{-methyl-2-butene}$
The mass percentage of carbon in $A$ is:

Assertion : Protonation of a carbonyl group increases its electrophilic character.
Reason : Protonation of a carbonyl group involves addition of an electrophile on nucleophilic oxygen.

Reduction of the lactol $S$ with sodium borohydride $(NaBH_4)$ gives:

Correct order for nucleophilic addition reaction :
$(1)$ $C_{6}H_{5}COC_{6}H_{5}$
$(2)$ $C_{6}H_{5}CHO$
$(3)$ $p-CH_{3}C_{6}H_{4}CHO$
$(4)$ $p-CH_{3}OC_{6}H_{4}CHO$

Which of the following reactions are incorrect?
$(a)$ $CH_2(COOH)_2 \xrightarrow{\Delta} CH_3COOH + CO_2$
$(b)$ Aniline $\xrightarrow{CH_3Cl/AlCl_3}$ $p$-chloroaniline
$(c)$ Phenol $\xrightarrow{CHCl_3 + aq. NaOH}$ Salicylic acid
$(d)$ $CH_3CHO + NaHSO_3 \rightleftharpoons CH_3CH(OH)SO_3Na$
$(e)$ Benzene $\xrightarrow{CO, HCl, Anhydrous AlCl_3/CuCl}$ Benzaldehyde