Arrange the following compounds in increasing order of their basicity:
$CH_3NH_2, (CH_3)_2NH, C_6H_5NH_2, (CH_3)_3N$

What is the major product obtained from the following reaction?

The major product of the reaction shown below is:

With respect to the following reaction,consider the given statements:
$C_6H_5NH_2 \xrightarrow{HNO_3, H_2SO_4, 288 \ K} \text{products}$
$(A)$ $o$-Nitroaniline and $p$-nitroaniline are the predominant products.
$(B)$ $p$-Nitroaniline and $m$-nitroaniline are the predominant products.
$(C)$ $HNO_3$ acts as an acid.
$(D)$ $H_2SO_4$ acts as an acid.

Give the structure of $A$ in the following reaction.
$2\text{-Nitro-4-methylaniline} \xrightarrow[(ii) \ H_3PO_2, H_2O]{(i) NaNO_2 + HCl, 273 - 278 \ K} A$.

The compound that forms a yellow oily liquid with nitrous acid is