A 63-year-old female presents for evaluation of a central vascular access device that was placed through the jugular vein. A pulsatile mass was noted in the patient's neck. What is the most likely cause of the pulsatile mass, and what would be expected on the ultrasound examination?

A) Aneurysm; Dilatation of the vessel wall would be seen on ultrasound.
B) Thrombosis; A blood clot obstructing the vessel would be visible on ultrasound.
C) Infection; Ultrasound would reveal signs of localized inflammation.
D) Hematoma; Accumulation of blood outside the vessel, detectable on ultrasound.