Which of the following is the strongest acid?

What will be the product $D$ in the following reaction?
$CH_3Cl$ $\xrightarrow{KCN} (A)$ $\xrightarrow{H_3O^+} (B)$ $\xrightarrow{NH_3} (C)$ $\xrightarrow{\Delta} (D)$

Consider the following molecules and statements related to them:
$(a)$ $(B)$ is more likely to be crystalline than $(A)$
$(b)$ $(B)$ has a higher boiling point than $(A)$
$(c)$ $(B)$ dissolves more readily than $(A)$ in water.
Identify the correct option from below:

Explain decarboxylation with examples. Or,provide the product obtained from the carboxylic acid method with examples.

What is the major organic product obtained in the following sequence of reactions?

Which one of the following compounds possesses the most acidic hydrogen $?$