Read the following passage and circle A, B, C or D to indicate the correct answer.
CITIES GOING GREEN
As more and more people concentrate in cities, planners are looking for ways to transform cities into better living spaces, ___(1)___ can be done by improving existing infrastructure while also creating more public ___(2)___ that are both beautiful and green. This can be hard to accomplish, especially in cities with a haphazard fashion. Some cities have been created with the idea of a green city as the goal. One such city, Masdar City in the United Arab Emirates, aims to become a model for ___(3)___ cities to follow. It is being known as a truly green city that relies strictly on renewable sources such as solar energy to provide all of its energy needs. ___(4)___, it will be a zero waste city in which everything that is used can be recycled. Whether it will truly accomplish its goal remains to be seen, but it will also act as an ___(5)___ for environmentally friendly areas to be tested.