According to the book of Job, which of the following is NOT a stated reason for Job's suffering, as explicitly denied or refuted within the dialogues?

A Secret sin committed by Job (denied by Job and his friends' failure to prove it) B A test of Job's faithfulness (suggested in the prologue, but not explicitly stated within the dialogues) C Divine retribution for the sins of Job's children D Correction or refinement of Job's character (implied by Elihu, but not directly stated as punishment)