Using the same facts above, but this time, unknowingly to Mr. X, his secretary received for him last April 14, 2022 a letter from the BIR which remained unopened. This letter contained a letter of authority from the BIR stating that the BIR is initiating an investigation over Mr. Xs financial books. Can Mr. X validly file his amended Income tax return on April 15, 2022? Why or why not? Explain fully but concisely.