One way kidney stones can form is when urine produced in the kidneys is overly concentrated with calcium or oxalate. Reducing dietary calcium has been thought, ttherefore, to decrease the likelihood that calcium will concentrate and form additional stones. Oddly enough, for many people the chances of recurrence are decreased by increasing calcium intake. Which one of the following, if true, most helps to resolve the apparent discrepancy described above? ['Increasing dietary oxalate while reducing dietary calcium does not reduce the chances of kidney stone recurrence.', 'Kidney stone development is sometimes the result of an inherited disorder that can result in excessive production of calcium and oxalate.', 'Some kidney stones are composed of uric acid rather than a combination of calcium and oxalate.', 'Increasing calcium intake increases the amount of calcium eliminated through the intestines, which decreases the amount to be filtered by the kidneys.']