Refer to the Following Graphs to Determine an Appropriate Response $x = y ^ { 2 }$

Multiple Choice

Refer to the following graphs to determine an appropriate response.
-Which is not the graph of a function? What is its equation?

A) graph B; $x = y ^ { 2 }$
B) graph $C ; y = \sqrt { x }$
C) graph A; $y = x$
D) graph D; $y = [ [ x ] ]$