[robstamos]

The correct answer to this question is both A and B. I'm having trouble understanding why D and C are not included as well since they follow the predicted acid strength going down the group due to increasing bond length and weakening hydrogen bond. Could someone help explain this?

Select all acid pairs that are arranged correctly according to predicted strength

A) H2S < H2Se
B) HBrO < HBrO2
C) H3PO4 < H3AsO4
D) HBrO < HIO