Answer:
B
Step-by-step explanation:
And arithmetic sequence is a sequence in which the difference between each of the numbers are constant.
It is not A, because the difference between 3 and 9 is positive 6, and the difference between 9 and 81 is positive 72.
It is not C, because the difference between 4 and 1 is -3, and the difference between 1 and 4 is positive 3.
It is not D, because the difference between 2 and -2 is -4, and the difference between -2 and 2 is positive 4.
And it is B because the numbers maintain a constant difference between each other, which is -3.
