Below Are the Structure and Individual Functional Group PK_a Values

Below are the structure and individual functional group pK_a values for the amino acid glutamic acid (abbreviated as Glu and/or E) .
Select all the true statement(s) :

A) At physiological pH (7.4) , all the carboxylic acid groups in Glu are dissociated.
B) At physiological pH (7.4) , none of the carboxylic acid groups in Glu are dissociated.
C) The net charge of Glu at pH 6 is +1.
D) The isoelectric point (pI) of Glu is 5.38.
E) The isoelectric point (pI) of Glu is 3.24.