$\mathrm{D}-(+)-$Glyceraldehyde $\underset{\begin{array}{l}\mathrm{ii})\hspace{0.17em}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}/{\mathrm{H}}^{\mathrm{+}}\\ \mathrm{iii})\hspace{0.17em}{\mathrm{HNO}}_{\mathrm{3}}\end{array}}{\overset{\mathrm{i})\hspace{0.17em}\mathrm{HCN}}{\to }}$

The products formed in the above reaction are

Two optically inactive products

One optically inactive and one meso product.

One optically active and one meso product

Two optically active products