This is a simple subtraction series.

Correct Option: A

This is a simple subtraction series. Each number is 35 less than the previous number.

This is a simple addition series.

Correct Option: B

This is a simple addition series. Each number increases by 2.

This is a simple subtraction series.

Correct Option: B

This is a simple subtraction series. Each number is 6 less than the previous number.

This is an alternation with repetition series

Correct Option: C

This is an alternation with repetition series in which each number repeats itself and then increases by 7.

This is a simple addition series with a random number, 8, interpolated as every other number.

Correct Option: D

This is a simple addition series with a random number, 8, interpolated as every other number. In the series, 6 is added to each number except 8, to arrive at the next number.