From an analysis of broken pottery and statuary, archaeologists have estimated that an ancient settlement in southwestern Arabia was established around 1000 B. C. However, new evidence suggests that the settlement is considerably older: tests show that a piece of building timber recently uncovered at the site is substantially older than the pottery and statuary. Which one of the following, if true, most seriously undermines the conclusion drawn from the new evidence? ['The building timber bore marks suggesting that it had been salvaged from an earlier settlement.', 'The pieces of pottery and fragments of statues that were analyzed come from several parts of the site.', 'The type of pottery found at the site is similar to a type of pottery associated with civilizations that existed before 1000 B. C.', 'The tests used to determine the age of the pottery and statuary had been devised more recently than those used to determine the age of the building timber.']