How many of the following acids will show higher reactivity towards esterification reaction as compared to acetic acid?

 $+{\mathrm{H}}_2\mathrm{O}$ $\underset{\mathrm{DiI}·H_2{\mathrm{SO}}_4}{\overset{{\mathrm{H}}_{\mathrm{g}}{\mathrm{SO}}_4,333\mathrm{K}}{\to }}\mathrm{X}\stackrel{\mathrm{Ba}(\mathrm{OH}{)}_2}{⟶}$ 

                                           $Y\stackrel{H^{+}/\Delta }{⟶}Z$

The ratio of number of $\sigma$ and $\pi$ bonds in the final product $\text{'}Z\text{'}$ is ______.

Number of all possible aldol products (including stereoisomers) are

The degree of unsaturation in major product $\left(\mathrm{B}\right)$ will be: