Which of the following is not an essential amino acid?

The $pH$ at the isoelectric point of three amino acids are given as follows:

Amino acid	$pH$ at Isoelectric point
$(Amino \ acid)_{I}$	$6$
$(Amino \ acid)_{II}$	$9.8$
$(Amino \ acid)_{III}$	$3.9$

$(Amino \ acid)_{II}$ is . . . . . . ?

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ solution of the product obtained by heating a mole of glycine with a mole of chlorine in the presence of red phosphorus generates a chiral carbon atom.
Reason $R$: $A$ molecule with $2$ chiral carbons is always optically active.
In the light of the above statements,choose the correct answer from the options given below:

Which of the following is not a function of proteins?

Identify the neutral amino acid from the following list represented by three-letter symbols.

Which of the following amino acids is basic in nature?