Answer: Choice A
This is because we're adding -6 to each term, i.e. subtracting 6 from each term, to get the next term
- -2+(-6) = -8
- -8+(-6) = -14
- -14+(-6) = -20
- -20+(-6) = -26
and so on. The gap between adjacent terms is the same width. We say that the common difference is d = -6.
