Patient, female, 25 years old, 10 days postnatal, lower abdominal pain with fever for 3 days, physical examination: T 39 ° C, P 98 / min, R 26 times / min. Purulent lochia with stench. Blood routine test: WB
C: 13x109 / L, N: 0.88. The most likely dianosis is:
选项：

A:puerperal infection;
B:puerperal heatstroke;
C:late postpartum hemorrhage;
D:acute cystitis