The biggest drawback to building green is
saving the environment
having to use green paint
the up front cost
the aesthetics of the new building

The biggest drawback to building green is the up front cost.

So the answer to this question is illustrated in the third option, stating "the up front cost". With the expensive and luxurious price tags on these green products lead users and consumers to believe that they become impractical. 

Not sure what you mean by this question