Give stream of consciousness and then the final answer. 5,9,18,31,52,__
Options:
(A) 79
(B) 80
(C) 86
(D) 82
(E) 83
(9+5) +4 = 18
(16+9) +6 = 31
(28+16)+8 = 52
(48+28)+10 = 86
The final answer: (C).