Concept:The series follows a simple arithmetic progression where each term increases by a constant difference. Explanation:The given series is 8, 13, 18, 23.Observe the difference between consecutive terms: 13 − 8 = 5, 18 − 13 = 5, 23 − 18 = 5.Each term is obtained by adding 5 to the previous term.Thus, the next term = 23 + 5 = 28.