The correct answer is B. Water has a lower viscosity than mercury.
Viscosity is a measure of how easily a fluid flows. A fluid with a high viscosity flows more slowly than a fluid with a low viscosity.
Water has a viscosity of 0.001 Pa·s, while mercury has a viscosity of 1.5 Pa·s. This means that water flows 150 times more easily than mercury.
The viscosity of a fluid is affected by its temperature. As the temperature of a fluid increases, its viscosity decreases. This is because the molecules in a fluid move faster as the temperature increases. When the molecules move faster, they are less likely to stick together, which makes the fluid flow more easily.
The viscosity of water is lower than the viscosity of mercury at all temperatures. This is because water molecules are smaller and lighter than mercury molecules. The smaller and lighter the molecules in a fluid, the faster they move. This is why water flows more easily than mercury.