ANSWER
The exponential equation is
[tex]a_n = 1({10})^{n - 1} [/tex]
EXPLANATION
The given geometric sequence is
[tex]1, 10, 100, 1000, ...[/tex]
The formula for finding the nth term of a geometric sequence is
[tex]a_n = a_1 {r}^{n - 1} [/tex]
where the first term is
[tex]a_1 = 1[/tex]
and the common ratio
[tex]r = \frac{a_2}{a_1} [/tex]
[tex]r = \frac{10}{1} = 10[/tex]
is the ratio between any two consecutive terms of the sequence.
We substitute these values to obtain,
[tex]a_n = 1({10})^{n - 1} [/tex]
The correct answer is C.