which statement is true regarding the conversion of arginine to ornithine in the urea cycle? a. the enzyme catalyzing this reaction is a hydrolase. b. this enzyme-catalyzed reaction occurs in the matrix. c. one of the products of this reaction is fumarate. d. the enzyme catalyzing this reaction is a ligase. e. the enzyme catalyzing this reaction is a hydrolase, and the reaction occurs in a matrix.