Answer:
None of the above
Step-by-step explanation:
According to the divergence test, if the limit of a sequence as n approaches infinity does not equal 0, then the series diverges. (Notice that if the limit does equal 0, the series doesn't necessarily converge).
According to the geometric series test, a geometric series converges if -1 < r < 1, and diverges otherwise.
The first series is a geometric series with r = -5/3. So it diverges.
The second series is also a geometric series:
3ⁿ⁻¹ / 2ⁿ = ⅓ (3ⁿ / 2ⁿ) = ⅓ (3/2)ⁿ
r = 3/2, so it diverges.
For the third series, the limit as n approaches infinity equals 1. This fails the divergence test, so this series also diverges.
For the fourth series, the limit as n approaches infinity equals 1. This fails the divergence test, so this series also diverges.
