There is a possibility but not extremely likely
Assuming it starts at rest, the roller coaster only has potential energy at the top of the hill, which is

When it reaches the bottom, its potential energy will have converted to kinetic energy,

where
is its velocity at that point. By the law of conservation of energy, assuming no loss of energy due to other sources (e.g. sound, heat), we have


Answer:
15km/h East (15m/s East option)
Explanation:
Velocity = (change in) Distance/(change in) Time
The distance here is 60km, and the time is 4h, as given by the question. Therefore the velocity is 60km/4h = 15km/h.
To convert km/h to m/s, we just divide the value by 3.6, 15/3.6= 4.17m/s (2dp), which isn't actually an option here, so I'm assuming maybe a mistake in unit for the question?
'Velocity' is a vector quantity, meaning it has a size<em> </em>and a direction, as opposed to speed, a scalar quantity, which only has size. Therefore we need to add a direction for it to be velocity. The given direction here is east, so the velocity of the car is 15km/h East. (I would choose the 15m/s East as the question likely has a unit error and is closest.)
Hope this helped!