Find the pair which is correctly matched

Nitrous acid (${\mathrm{HNO}}_2$) converts amino acids into hydroxy acids with retention of configuration. Estimation of nitrogen gas evolved in the reaction is the basis of Van slyke estimation of amino acids.

Which of the following amino acids cannot be analysed by Van slyke method?

 (cysteine)

 (Proline)

 (Histidine)

 (Valine)

Calculate of $\mathrm{PI}$ of glutamic acid

Glucose

The correct statements about above structure of glucose are:

Fructose

The product $\mathrm{A}$ and $\mathrm{B}$ in the a above reaction are: