It would be Parallel circuits as people want the lights to be brighter as each bulb has its own path. Other than that, there are many electrical appliances that have to run independent of each other in a house. If one appliance is turned on or off it should not affect the other appliances. If arranged in series, the other appliances cannot be switched on independently as they share the same pathway. Therefore, the answer should be parallel circuits.
Hope this helped :)