Formation of the Curved Upper Surface, Such as Occurs in a Tube

Formation of the curved upper surface, such as occurs in a tube filled with water, is an important factor in plant water movement. A curved upper surface is created by ________.

A) the upward pull of gravity on the water column in the tube
B) downward pressure from the atmosphere on the topmost layer of water molecules
C) the water molecules being pulled upward by adhesion to the air
D) the topmost layer of water molecules being pulled downward by the hydrogen bonds to the water molecules below