A Sequence $a_{n}$ Can Be Defined by a Recurrence Relation, Which Gives the Which

Multiple Choice

A sequence $a_{n}$ can be defined by a recurrence relation, which gives the first term, $a_{1}$ , and a formula for finding $a_{n}$ in terms of the previous term, $a_{n-1}$ . For the recurrence relation below, what is the formula for the general term?
$a_{1}=1 ; a_{n}=\frac{a_{n-1}}{9}$

A) $a_{n}=\left(\frac{1}{9}\right) ^{n}$
B) $a_{n}=\left(\frac{1}{9}\right) ^{n-1}$
C) $a_{n}=\frac{1}{9 n}$
D) $a_{n}=\frac{1}{9(n-1) }$