Final answer:
The likely cause of grease accumulation in a kitchen is a malfunctioning ventilation system that fails to remove cooking fumes and grease properly.
Step-by-step explanation:
The most likely cause of grease accumulation on the ceiling and walls of the kitchen is that the ventilation system is not working properly.
When a kitchen's ventilation system, such as an exhaust fan or hood, fails to function effectively, it doesn't remove cooking fumes and grease from the air as it should.
This can cause grease to settle on surfaces, including the ceiling and walls.
Overcooked food typically leads to localized burning or charring, dishwashing area cleanliness affects the immediate vicinity, and pest infestations have different signs, like droppings and damage to packages or food.