This is an alternating series. Pattern 1 (odd positions): 8, 11, 14, 17, 20, 23... (+3 each time). Pattern 2 (even positions): 7, 12, 17, 22... (+5 each time). The series at position 9 should follow Pattern 1: 17 + 3 = 20. So the next term is 20, making option A correct.