Equatorial currents are primarily westward. This is because the dominant current in the northern hemisphere has a clockwise direction, while the southern hemisphere has a counterclockwise direction. When these two currents meet at the equator, a common westward current exists.
I assume the block plows into the bank of sand with a velocity of 6 m/s and comes to a stop in 2 s.
The answer is C, because the water molecules are evaporating and the salt molecules are staying the same.