Which one of the following is classified as a contact force?

Which of the following statements is/are NOT correct? I. Force per unit volume is defined as pressure. II. Liquids exert pressure on the walls of their container. III. A force acting on an object can change its state of motion but can never alter its shape.

The effect of thrust on a surface depends on the area on which it acts. Force acting on a smaller area exerts a ___________ compared to a larger area.