Which of the following is more basic than aniline?

Reaction of $R-CONH_2$ with a mixture of $Br_2$ and $KOH$ gives $R-NH_2$ as the main product. The intermediates involved in this reaction are :-
$(A)$ $R-CONHBr$
$(B)$ $R-NH-Br$
$(C)$ $R-N=C=O$
$(D)$ $R-CONBr_2$

Identify product $D$ in the following reaction sequence:
$CH_3-C(CH_3)_2-CH_2-CH_2-OH$ $\xrightarrow[H_2O, \text{heat}]{K_2Cr_2O_7, H_2SO_4} A$ $\xrightarrow{SOCl_2} B$ $\xrightarrow{2(CH_3)_2NH} C$ $\xrightarrow[2. H_2O]{1. LiAlH_4, \text{diethyl ether}} D$

The major product formed in the following reaction is:

Arrange the following compounds in their correct order of $pK_b$ values.

Among the following compounds,the most basic compound is