Identify the Domain and Range of a Function from Its $( - \infty , \infty )$

Identify the Domain and Range of a Function from Its Graph
Use the graph to determine the function's domain and range.
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A) domain: $( - \infty , \infty )$
range: $( - \infty , \infty )$
B) domain: $( - \infty , \infty )$
range: $\mathrm { y } = 1$
C) domain: $x = \frac { 1 } { 2 }$
range: $( - \infty , \infty )$
D) domain: $x = \frac { 1 } { 2 }$
range: $y = 1$