Better method for preparation of $$\mathrm{BeF}_{2}$$, among the following is :

The major product for the following reaction is:

The naturally occurring amino acid that contains only one basic functional group in its chemical structure is

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

Assertion A : Isotopes of hydrogen have almost same chemical properties, but difference in their rates of reaction.

Reason R : Isotopes of hydrogen have different enthalpy of bond dissociation.

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