Of the Given Values Of $x$ , Identify Those at Which the Function Is Continuous

Multiple Choice

Of the given values of $x$ , identify those at which the function is continuous.
- $f(x) =\frac{x^{2}-81}{x-9} ; x=-9,0,9$

A) $9,-9$
B) $-9,0,9$
C) 0,9
D) $-9,0$