What is the IUPAC name of the product Y in the given reaction sequence?

3,4,5 - trihydroxy hexanoic acid
The reaction sequence starts with an aldehyde group, which reacts with cyanide to form a cyanohydrin intermediate. Upon hydrolysis, the cyano group is converted into a carboxyl group, resulting in hexahydroxyheptanoic acid as the product Y.

In a messenger RNA molecule, untranslated regions (UTRs) are present at:
I. 5' end before start codon
II. 3' end after stop codon
III. 3' end before stop codon
IV. 5' end after start codon