When a moving bus suddenly stops, passengers feel a jerk. This is a result of:

Motion inertia can be defined as if a body is already in motion, it will tend to continue in that same state of motion (with the same speed and direction) unless an external unbalanced force acts on it to change that state of motion.

According to the question, when the bus stops, the passengers feel a jerk. We know this because people were moving along with it while the bus was travelling. As a result, they had inertia of motion. When the bus comes to a complete stop, its inertia shifts from that of motion to that of rest. However, people's inertia remains that of motion. As a result, they feel a jerk.