Indicator Problem?

Question

In the titration of a weak acid HA with 0.100 M NaOH, the stoichiometric point is known to occur at a pH value of approximately 11. Which of the following indicators would be best to use to mark the endpoint of this titration?

A. an indicator with Ka = 10^-6
B. an indicator with Ka = 10^-8
C. an indicator with Ka = 10^-14
D. an indicator with Ka = 10^-12

Answer 1

d