The PK₁,pK₂,and PK_R for the Amino Acid Aspartic Acid Are $\alpha$

The pK₁,pK₂,and pK_R for the amino acid aspartic acid are 2.0,9.9,and 3.9,respectively.At pH 7.0,aspartic acid would be charged predominantly as follows:

A) " $\alpha$ -carboxylate 0, $\alpha$ -amino +1, $\beta$ -carboxylate 0,net charge +1"
B) " $\alpha$ -carboxylate −1, $\alpha$ -amino +1, $\beta$ -carboxylate −1,net charge −1"
C) " $\alpha$ -carboxylate 0, $\alpha$ -amino −1, $\beta$ -carboxylate 0,net charge −1"
D) " $\alpha$ -carboxylate +1, $\alpha$ -amino −1, $\beta$ -carboxylate +1,net charge +1"
E) " $\alpha$ -carboxylate +1, $\alpha$ -amino +1, $\beta$ -carboxylate +1,net charge +3"