Determine Whether the Linear Equation Defines $y$ To Be a Function Of

Determine whether the linear equation defines $y$ to be a function of $x$ . If so, find the domain and range. $y = \frac { 1 } { 3 } x - 1$

A) domain: $( - \infty , 0 )$ ; range: $( 0 , \infty )$
B) domain: $( 0 , \infty )$ ; range: $( - \infty , \infty )$
C) domain: $( - \infty , \infty )$ ; range: $( - \infty , \infty )$
D) domain: $( - \infty , \infty )$ ; range: $( 0 , \infty )$
E) $y$ is not a function of $x$