The titration shown here has an equivalence point at pH = 3.2. Identify which of the following indicators would be appropriate for this titration. Check all that apply.
a. metacresol purple pKa = 1.51, 8.32
b. ethyl red pKa = 5.42
c. quinaldine red pKa = 2.63
d. bromothymol blue pKa = 7.0
e. phenolphthalein pKa = 9.50
f. thymol blue pKa = 1.65, 9.20