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.
- $f(x) =\frac{|x-9|}{x+9} ; x=-9,0,9$

A) None
B) $9,0,-9$
C) 0,9
D) $-9,0$