Choose the incorrect statement among the following.
$A$. The reactivity of aromatic aldehydes and ketones is less than that of aliphatic carbonyl compounds towards nucleophilic addition reactions.
$B$. Benzaldehyde does not give Fehling's test.
$C$. The $\alpha$-$H$ atoms in ethanal are acidic in nature.
$D$. $p$-nitro benzaldehyde is less reactive than benzaldehyde towards nucleophilic addition reactions.

Given below are two statements:
Statement $I$: $H_2N-CO-CH_2-CH_2-CO-CH_3$ under Clemmensen reduction conditions will give $HOOC-(CH_2)_3-CH_3$.
Statement $II$: $CH_3-CH(CH_3)-CH_2-CH(Cl)-CO-CH_3$ under Wolff-Kishner reduction conditions will give $CH_3-CH(CH_3)-CH_2-CH(Cl)-CH_2-CH_3$.
In the light of the above statements,choose the correct answer from the options given below:

What is $X$ in the following reaction?
$2 CH_3COCH_3 \stackrel{Ba(OH)_2}{\longrightarrow} X$

Complete reaction of acetaldehyde with excess formaldehyde,upon heating with conc. $NaOH$ solution,gives $P$ and $Q$. Compound $P$ does not give Tollens' test,whereas $Q$ on acidification gives positive Tollens' test. Treatment of $P$ with excess cyclohexanone in the presence of catalytic amount of $p$-toluenesulfonic acid $(PTSA)$ gives product $R$. Sum of the number of methylene groups $(-CH_2-)$ and oxygen atoms in $R$ is....

Acetaldehyde and acetone can be distinguished by

Butanone reacts with methyl magnesium bromide to form an addition product $(Z)$. On hydrolysis,$(Z)$ gives: