Concept:A number series follows a fixed pattern, and the odd term breaks that pattern.Explanation:Compare consecutive terms to find the differences.64−62=2, so the first change is −2.62−58=4, so the next change is −4.58−52=6, so the next change is −6.The pattern should continue with a change of −8.But 52−42=10, so the actual change is −10, not −8.Thus, 42 does not fit the pattern.The correct term should be 52−8=44.Answer:42 is the odd man out, i.e., Option C.