A car suddenly changes direction while moving at constant speed. Which aspect of inertia is being demonstrated, and how does the car’s mass influence this effect?

The correct option is: "The inertia of direction is demonstrated, and a car with greater mass will resist the change in direction more."

Here is a step-by-step explanation of the physics principles demonstrated in this scenario:

1. Understanding Inertia of Direction:
Inertia is the inherent property of an object to resist any change in its state of rest or of uniform motion. Inertia can be classified into three types: inertia of rest, inertia of motion (or speed), and inertia of direction.
Inertia of direction is the inability of a body to change its direction of motion by itself. When a car suddenly changes direction, its passengers or the car itself tends to maintain the original straight-line path. This tendency to resist a change in the direction of motion is known as the inertia of direction.

2. The Influence of Mass on Inertia:
Mass is the quantitative measure of inertia. The greater the mass of an object, the greater is its resistance to any change in its state of motion (which includes speed and direction).
Mathematically, according to Newton's first law of motion, to change the velocity (which has both magnitude/speed and direction) of an object, an external force must be applied. The required force $F$ to produce a change in direction is directly proportional to the mass $m$ of the object. Therefore, a car with a greater mass possesses more inertia and will resist a change in its direction of motion more than a lighter car.