Much of the best scientific research of today shows that many of the results of earlier scientific work that was regarded in its time as good are in fact mistaken. Yet despite the fact that scientists are above all concerned to discover the truth, it is valuable for today' s scientists to study firsthand accounts of earlier scientific work. Which one of the following, if true, would best reconcile the two statements above? ['Scientists can make valuable contributions to the scientific work of their time even if the results of their work will later be shown to be mistaken.', 'Lessons in scientific methodology can be learned by seeing how earlier scientific work was carried out, sometimes especially when the results of that work are known to be incorrect.', 'There are many scientists today who are not thoroughly familiar with earlier scientific research.', 'Many firsthand accounts of earlier, flawed scientific work are not generally known to be mistaken.']