Answer: B. Motor oil that is in the refrigerator
Step-by-step explanation:
Viscosity can be defined as the resistance provided by the fluid against its movement or flow. It restricts the resistance to change in shape or movement of fluid. The water has high viscosity as the water molecules do not restrict movement on the surface.
According to the given problem, motor oil has lowest viscosity because it may contain heavy hydrocarbons, which may restrict its flow also when kept in refrigerator, the bonds between hydrocarbons get compact hence, viscosity decreases.