If f is a function and x is an element of its domain, then which of these is correct? a. f ( x ) denotes the output corresponding to the input x, and the graph of the function is y = f ( x ) .
b. f ( x ) denotes the output corresponding to the input x, and the graph of the function is x = f ( y ) .
c. f ( x ) denotes the input corresponding to the output x, and the graph of the function is y = f ( x ) .
d. f ( x ) denotes the input corresponding to the output x, and the graph of the function is x = f ( y ) .