Which amino acid does not contain any chiral carbon-

Which amino acid does not contain chiral centre ?

Which amino acid does not contain chiral centre ?

Which of the following alpha -amino acids does not contain a chiral carbon ?

An example of a molecule which is chiral but does not contain chiral carbon atom is :

Which amino acid is chiral-

From the above compounds select : (A) two of which are chiral and contain chiral centre : _____ (B) two of which are achiral and contains chiral centre : _______ (C) two of which are chiral and does not contain chiral centre : ______ (D) two of which are achiral and does not contain chiral centre : _______.