(Hint: Let $x = \rho \sin \phi \cos \phi , y = \rho \sin \phi \sin \theta$

Multiple Choice

$\text { Use spherical coordinates to find the limit } \lim _ { ( x , y , z ) \rightarrow ( 0,0,0 ) } \frac { 9 x y z } { 9 x ^ { 2 } + 9 y ^ { 2 } + 9 z ^ { 2 } } \text {. }$ (Hint: Let $x = \rho \sin \phi \cos \phi , y = \rho \sin \phi \sin \theta$ , and $z = \rho \cos \phi$ , and note that $( x , y , z ) \rightarrow ( 0,0,0 )$ implies $\left. p \rightarrow 0 ^ { + } . \right)$

A) 6
B) 9
C) 1
D) 7
E) 0