Question:
Solution:
According to the data of the problem, the series is given by the following expression:

now, remember the ratio test:
Suppose we have the series

Define,

Then,
if L<1, the series is absolutely convergent (and hence convergent).
if
L>1, the series is divergent.
if
L=1 the series may be divergent, conditionally convergent, or absolutely convergent.
Applying this definition to the given series, we obtain:

then, the given series is absolutely convergent (and hence convergent). So that, we can conclude that the correct answer is: