All structures given below are of vitamin C. Most stable of them is :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : $$\alpha$$-halocarboxylic acid on reaction with dil. $$\mathrm{NH_3}$$ gives good yield of $$\alpha$$-amino carboxylic acid whereas the yield of amines is very low when prepared from alkyl halides.

Reason (R) : Amino acids exist in zwitter ion form in aqueous medium.

In the light of the above statements, choose the correct answer from the options given below :

The correct representation in six membered pyranose form for the following sugar [X] is

Match List I with List II

Choose the correct answer from the options given below :