A) But already, some of the model cities mapped out early on, like Gamacapital, an eco-city that was to house 500,000 people on Chongming Island near Shanghai, have been abandoned because of a range of problems like official corruption and confusion over how the projects would be financed.
B) But already, some of the model cities mapped out early on, such as Gamacapital, an eco-city that was to house 500,000 people on Chongming Island near Shanghai, abandoned due to a range of problems like official corruption and confusion over how the projects would be financed.
C) But already, some of the model cities that had been mapped out early on, such as Gamacapital, an eco-city that was to house 500,000 people on Chongming Island near Shanghai, abandoned due to a range of problems such as official corruption and confusion over how the projects would be financed.
D) But already, some of the model cities mapped out early on, such as Gamacapital, an eco-city that was to house 500,000 people on Chongming Island near Shanghai, were abandoned due to a range of problems such as official corruption and confusion over how the projects would be financed.
E) But already, some of the model cities mapped out early on, such as Gamacapital, an eco-city that was to house 500,000 people on Chongming Island near Shanghai, have been abandoned because of a range of problems such as official corruption and confusion over how the projects would be financed.
A, B - usage of like to present example.
C,D - usage of "due to" for reasoning.
Hence, E is the Answer.