The kinetic theory of gases states that a gas consists of many molecules in constant motion. A rise in temperature increases the mean speed of these molecules, and therefore their momentum (=mv).
The increased momentum of these molecules results in more frequent and more forceful collisions with the walls of the container. Pressure is defined as force/area. As we are told that the volume, and therefore the area of the walls of the container remain the same, the increased force of the colliding gas molecules must result in an increased pressure within the container.