Using Data from the Previous Problem, What Fraction of the HSc^-

Using data from the previous problem, what fraction of the HSc^- formed in the first step of the dissociation of succinic acid goes on to dissociate to form Sc^2- ions in the second step, and what does this lead us to conclude?

A) None of the HSc^- ions dissociate further, and the stepwise dissociation assumption is legitimate.
B) Less than 1% of the HSc^- ion dissociate to form Sc^2- ions, and the stepwise dissociation assumption is legitimate.
C) Between 1 and 5% of the HSc^- ions dissociate, and the stepwise dissociation assumption is legitimate.
D) Between 5 and 20% of the HSc^- ions dissociate, and the stepwise dissociation assumption is legitimate.
E) Between 5 and 20% of the HSc^- ions dissociate, and the stepwise dissociation assumption is not legitimate.