A dipeptide, " $x$ " on complete hydrolysis gives " $y$ " and " $z$ ". " $y$ " on treatment with aq. $\mathrm{HNO}_2$ produces lactic acid. On the other hand " z " on heating gives the following cyclic molecule.

Based on the information given, the dipeptide $X$ is :

Identify the pair of reactants that upon reaction, with elimination of HCl will give rise to the dipeptide Gly-Ala.

Fat soluble vitamins are:

A. Vitamin $\mathrm{B}_1$

B. Vitamin C

C. Vitamin E

D. Vitamin B 12

E. Vitamin K

Choose the correct answer from the options given below:

$$ \text { Which of the following is the correct structure of L-Fructose? } $$