Arrange the following in the correct order of the rate of Nucleophilic Addition Reaction $(NAR)$:
$(I) \ HCHO$
$(II) \ CH_3CHO$
$(III) \ p-NO_2-C_6H_4CHO$
$(IV) \ p-CH_3-C_6H_4CHO$

Statement-$I$ :- Acetaldehyde and acetone can be distinguished by Tollen's reagent.
Statement-$II$ :- Aromatic aldehyde does not give Fehling test.

The products $A$ and $B$ of the below reaction sequence are

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.

In the given Cannizzaro reaction,the slowest step is:
$2PhCHO \xrightarrow{KOH} PhCH_2OH + PhCOO^-$

Identify the reagents $S$ and $\mu$ in the scheme below in which $R$ is converted to the nitrile via the benzylic halide. $R, S$ and $\mu$ respectively are: