Roni wants to write an equation to represent a proportional relationship that has a constant of proportionality equal to Start Fraction 7 over 25 End Fraction. She writes the equation y = x + Start Fraction 7 over 25 End Fraction. What error is Roni making?
A. She should have written y = negative x + StartFraction 7 over 25 EndFraction so that x and y have a constant sum.
B. She should have written x y = StartFraction 7 over 25 EndFraction so that x and y have a constant product.
C. She should have written y = StartFraction 7 over 25 EndFraction x so that x and y have a constant quotient.
D. She should have written y = StartFraction 7 over 25 EndFraction so that y has a constant value.