**Core Concept**
Ectopic pregnancy is a life-threatening condition where the embryo implants outside the uterus, most commonly in the fallopian tube. The presentation of ectopic pregnancy can be variable, but some signs are more reliable than others. In this context, the question is asking about the most consistent sign in disturbed (or ruptured) ectopic pregnancy.

**Why the Correct Answer is Right**
The correct answer is the adnexal mass, which is a palpable mass in the adnexal region. This is due to the accumulation of blood and debris from the ruptured ectopic pregnancy. The presence of an adnexal mass, often accompanied by pain, is the most consistent sign of a ruptured ectopic pregnancy. This is because the fallopian tube, where the ectopic pregnancy typically occurs, is located in the adnexal region, making it a common site for palpation.

**Why Each Wrong Option is Incorrect**
**Option A:** Hematuria is not a consistent sign of ectopic pregnancy, although it can occur in cases where the ectopic pregnancy ruptures into the peritoneal cavity and irritates the urinary bladder.

**Option B:** Abdominal pain is a common symptom of ectopic pregnancy, but it is not a consistent sign that can be relied upon for diagnosis.

**Option C:** Amenorrhea (absence of menstruation) is a nonspecific symptom that can occur in many conditions, including pregnancy, but it is not a consistent sign of ectopic pregnancy.

**Clinical Pearl / High-Yield Fact**
Remember that a ruptured ectopic pregnancy can present with a triad of abdominal pain, adnexal mass, and hemodynamic instability.

**Correct Answer: . Adnexal mass.**