Answer
=0 km
Work Step by Step
In straight line motion, displacement is measured as the straight line distance between initial and final points.
Displacement, $\Delta x$=$x_f-x_i$
Here, $x_i$ is the initial position and $x_f$ is the final position with respect to some origin.
Since bee came back to the hive, $x_i=x_f$.
Therefore,
$\Delta x$=$x_f$-$x_i$
=0-0
=0 km
