What does the picture tell you about how ships pass through the St. Lawrence Seaway?

Question

a) Ships cannot travel from the St. Lawrence River to the Great Lakes, but must offload their products to be carried overland.
b) Ships move from west to east or from east to west, but not in a north-south direction.
c) Ships move from higher water levels to lower ones through a series of locks over several bodies of water.
d) Ships that travel on Lake Ontario cannot travel on the other lakes because of the distance in altitude.

Answer 1

c) Ships move from higher water levels to lower ones through a series of locks over several bodies of water.