Which of the following is most reactive for decarboxylation?

When compound $A$ reacts with methyl alcohol in the presence of a few drops of $H_2SO_4$,it forms oil of wintergreen. What is compound $A$?

Propionic acid with $Br_2/P$ yields a dibromo product. Its structure would be:

Which of the following pairs of reagents is used for the conversion of a carboxylic acid to a primary alcohol?

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:

$A$ liquid was mixed with ethanol and a drop of concentrated $H_2SO_4$ was added. $A$ compound with a fruity smell was formed. The liquid was :