Look at this series: 70, 71, 76, __, 81, 86, 70, 91, ... What number should fill the blank?  Pick one:  A) 60  B) 70  C) 82  D) 77  E) 52
70   70   In this series, 5 is added to the previous number; the number 70 is inserted as every third number.
<result>B</result>
Look at this series: 70, 71, 76, __, 81, 86, 70, 91, ... What number should fill the blank?