Answer:
a
Explanation:
Distance is simply the distance travelled which in this case would be 4km + 3km = 7km
To work out displacement, try to imagine the situation.
Draw a straight line to the east (label it 3) and then draw another line from the end of the first line upwards (label this one 4). Thus, you've created a right angles triangle. Now use pythagorean theorem to work out the displacement
4^2 + 3^2 = 25
sqrt 25 = 5 = displacement