(a) A claim or part of a claim that has been rejected by the personal representative is barred unless not later than the 90th day after the date of rejection the claimant commences suit on the claim in the court of original probate jurisdiction in which the estate is pending.
(b) In a suit commenced on the rejected claim, the memorandum endorsed on or attached to the claim, or any other memorandum of rejection filed with respect to the claim, is taken to be true without further proof unless denied under oath.