$R + CH_3-CO-CH_3 \xrightarrow{H^{+}} \text{Schiff's base}$. What is $R$ in this reaction?

Which of the following has the highest $pK_b$ value?

What is the expected order of basic strength of different compounds from the following in the aqueous phase?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: Experimental reaction of $CH_{3}Cl$ with aniline and anhydrous $AlCl_{3}$ does not give $o-$ and $p-$methylaniline.
Reason $(R)$: The $-NH_{2}$ group of aniline becomes deactivating because of salt formation with anhydrous $AlCl_{3}$ and hence yields $m-$methylaniline as the product.
In the light of the above statements,choose the most appropriate answer from the options given below.

The decreasing order of basicity is:
$(1) \ CH_3CONH_2$
$(2) \ CH_3CH_2NH_2$
$(3) \ PhCH_2CONH_2$

The relation between $(A)$ and $(B)$ is:
$CH_3-CONH_2 \xrightarrow{KOBr} (A)$
$CH_3-CONH_2 \xrightarrow{LiAlH_4} (B)$