Find the Function Value $f ( x ) = \frac { 1 } { 3 } x$

Find the function value.
-Find f(6) when $f ( x ) = \frac { 1 } { 3 } x$

A) $- \frac { 1 } { 2 }$
B) 2
C) $\frac { 1 } { 2 }$
D) -2