Sean used cross multiplication to correctly solve a rational equation. He found one valid solution and one extraneous solution. If 1 is the extraneous solution, which equation could he have solved? A. The equation is = because 1 makes a denominator equal zero and is a solution of the equation derived from cross multiplying. B. The equation is = because 1 is a solution of both the original equation and the equation derived from cross multiplying. C. The equation is = is because 1 makes a numerator equal zero and is a solution of the equation derived from cross multiplying. D. The equation is = because 1 makes a denominator equal zero and is not a solution of the equation derived from cross multiplying.