Which molecules would most likely cause a liquid to have the lowest viscosity? large, polar molecules small, nonpolar molecules

Small, non polar molecules.

Explanation:

Viscosity is a property of a liquid which is similar to friction or drag. When a liquid has high viscosity, it flows slowly and when it flows easily, the liquid is said to be less viscous.

Polar molecules will share the electrons in the covalent bonds unequally. Liquids that have polar bonds are said to have higher viscosity.

In non polar bonds, atoms have equal electronegativity.

Smaller nonpolar molecules