Predict the stereochemistry of the product when a $d$ and $l$-amine mixture reacts with an $l$-acid.

Consider the following reaction sequence:
$p$-Nitrotoluene $\xrightarrow{P} Q$ $\xrightarrow{R} S$ $\xrightarrow{H_2O} T$
$S \xrightarrow{U} \text{Benzoic acid}$
Identify the correct statements from the following:
$(A) P = H_2/Pd, \text{ethanol}; R = NaNO_2/HCl; U = 1. H_3PO_2, 2. KMnO_4-KOH, \text{heat}$
$(B) P = Sn/HCl; R = HNO_2; S = p-\text{toluenediazonium chloride}$
$(C) S = p-\text{toluenediazonium chloride}; T = p-\text{cresol}; U = 1. CH_3CH_2OH, 2. KMnO_4-KOH, \text{heat}$
$(D) Q = p-\text{nitrobenzoic acid}; R = H_2/Pd, \text{ethanol}; T = p-\text{cresol}$
Which of the following combinations is correct?

What are $X$ and $Y$ respectively in the following set of reactions?

The major product $Z$ formed in the following sequence of reactions is:

Product $D$ is:-

$90 \ g$ of ethylamine on reaction with methyl chloride produces a tertiary amine as the exclusive product. The amount of methyl chloride required is:
$[\text{Given atomic masses in amu}: H=1, C=12, N=14, Cl=35.5]$ (in $g$)