Answer: C
O03.0 is an appropriate code for this case because it is used to specify the infection in the genital tract and pelvis following incomplete spontaneous abortion.
Option A is not correct because O03.1 is used to specify delayed or excessive hemorrhage following incomplete spontaneous abortion.
Option B is not correct because O03.4 is used to specify incomplete spontaneous abortion without complication.
Option D is not correct because O037 is used to specify embolism following complete or unspecified spontaneous abortion.