The correct answers are: a roller coaster, a farm and an office building.
Built environment or built world are human-made surroundings that provide the settings for a particular human activity. They are human-made places where people live, work and recreate on a daily basis. They can be buildings, parks and transportation systems.
They are to be distinguished from a natural environment. A city park is an example of a built environment, a wild jungle is not.
A roller coaster is a place used for recreational purposes and man-made.
A farm, even if established on a wild, previously unoccupied field, is a built environment as it had been modified by humans to cater for and to adopt for their needs.
An office building is a place that only exists because humans built it, it is therefore, the perfect example of a built environment.