Which of the following statements about the acute nephritic syndrome is incorrect?
选项：

A:Hypertension and edema rarely occur.;
B:It is characterized by hematuria, proteinuria, azotemia, and hypertension.;
C:It usually has an acute onset and is caused by inflammatory lesions of glomeruli. ;
D:Patient with nephritic syndrome may tell you that he has dark urine.