This is a simple alternating subtraction series,

Correct Option: A

This is a simple alternating subtraction series, which subtracts 2, then 5.

This alternating addition series begins with 3; then 1 is added to give 4;

Correct Option: D

This alternating addition series begins with 3; then 1 is added to give 4; then 3 is added to give 7; then 1 is added, and so on.

In this simple alternating subtraction and addition series;

Correct Option: C

In this simple alternating subtraction and addition series; 1 is subtracted, then 2 is added, and so on.

This is an alternating number subtraction series.

Correct Option: B

This is an alternating number subtraction series. First, 2 is subtracted, then 4, then 2, and so on.

This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next.

Correct Option: A

This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.