For each of the following, decide if the given series is a geometric series.

*A.* \(5 + 5 x + 5 x^2 + 5 x^4 + 5 x^8 + \cdots\) :

Is this a geometric series?

If this is a geometric series, enter

the first term:

and the ratio between successive terms:

*(Enter* *na* *for the first term and ratio if this is not a geometric series.)*

*B.* \(5 x^5 + 5 x^{6} + 5 x^{7} + 5 x^{8} + \cdots\) :

Is this a geometric series?

If this is a geometric series, enter

the first term:

and the ratio between successive terms:

*(Enter* *na* *for the first term and ratio if this is not a geometric series.)*

*C.* \(5 - 25 + 125 - 625 + 3125 - \cdots\) :

Is this a geometric series?

If this is a geometric series, enter

the first term:

and the ratio between successive terms:

*(Enter* *na* *for the first term and ratio if this is not a geometric series.)*