Maximize the Confusion of an Exam

You are taking an exam that consists of multiple-choice questions. Each question has one correct answer among four choices labeled 'A', 'B', 'C', and 'D'. The exam is designed in such a way that for each question, the letter representing the correct answer is randomly shuffled amongst the four choices.

You are given a string answerKey, which is the correct answer to each question, and an integer k. You can replace at most k characters of the answer sheet.

Return the maximum number of consecutive questions the student has answered correctly after making the allowed replacements.