Final answer:
The 30-year-old woman's symptoms and ultrasound findings point to a ruptured ectopic pregnancy, which is a serious condition requiring immediate medical intervention. Option a.
Step-by-step explanation:
In this scenario, the 30-year-old woman is exhibiting symptoms that suggest a ruptured ectopic pregnancy, as evidenced by acute onset abdominal pain, nausea, involuntary guarding, and tenderness to percussion, along with a positive pregnancy test and ultrasound findings.
An ectopic pregnancy is a medical emergency where a fertilized egg implants outside the uterine cavity, most commonly in the fallopian tube, which can result in life-threatening internal bleeding if the structure containing the embryo ruptures.
This condition is distinct from appendicitis, acute cholecystitis, and other gastrointestinal or urological infections that may present similarly but lack the pregancy-related ultrasound findings.
Immediate medical intervention is critical to address this condition and may include surgery to remove the ectopic tissue and stop the bleeding, and in some cases, stabilization of the patient's hemodynamic status. Option a.