Option 1: It will cool the room. This option suggests that keeping the door of a running refrigerator open in a closed room will lead to the room getting cooler. However, this is incorrect. The refrigerator works by removing heat from the inside, so keeping the door open will simply release the cool air from the refrigerator into the room, without actively cooling the room.

Option 2: It will heat the room. This option is correct. When the door of a running refrigerator is kept open in a closed room, the refrigerator will continue to extract heat from its internal components. This excess heat will then be released into the room, causing the room to heat up over time.

Option 3: It will make no difference on the average. This option is incorrect. As explained in option 2, keeping the door of a running refrigerator open will result in the release of excess heat into the room, resulting in a net increase in temperature.

Option 4: It will make the temperature go up and down. This option is not necessary to consider as it does not accurately describe what will happen when the door of a running refrigerator is kept open in a closed room.