According to the Diagram, Does This Amino Acid Have a Titratable

According to the diagram, does this amino acid have a titratable R-group?

A) yes, as evidenced by the steep center of the curve
B) yes, as evidenced by the two relatively flat parts of the curve
C) no, as evidenced by only two relatively flat parts of the curve
D) no, as evidenced by the steepness of the center of the curve
E) It cannot be determined from this graph.