Jennifer Bungee-Jumps from a Bridge (Event A) $A$ And One Present at Event

Multiple Choice

Jennifer bungee-jumps from a bridge (event A) . Jennifer's bungee cord is perfectly elastic, so she bounces exactly back up to the bridge and lands on her feet (event B) . The time between these events is measured by Jennifer's watch, a stopwatch held by Jennifer's friend, Rob, who is standing on the bridge, and by two passengers (one present at event $A$ and one present at event $B$ ) who are riding on a train traveling at a constant velocity across the bridge at the time (the passengers have synchronized watches and compare readings later) . Assuming the earth's frame is inertial, who measures
-(c) the space time interval between the events?

A) Jennifer
B) Rob
C) The train passengers