What is -1/6 multiplied by 6

Which of the following are arithmetic sequences? check all that apply. a. 0.3, 0.6, 0.9, 1.2, 1.5, b. 2, 3, 6, 11, 18, c. 150, 147, 144, 142, d. 2, 4, 9, 16, 25,