Answer: Geotagging was enabled on her smartphone
Step-by-step explanation:
The security weakness that is the most likely cause of the security breach is that geotagging was enabled on the vice president's smartphone.
Geotagging, occurs when geographical identification metadata are added to websites, photograph, video, etc. Geotagging can be used to get the location of particular place.
In this case, since geotagging was enabled on her smartphone, it was easy for the attacker to locate her house.