Which of the Following Is a True Statement Regarding Sustainable

Which of the following is a true statement regarding sustainable building design?
1) Construction costs are usually less than traditional building practices.
2) There are currently no agreed-upon standards, making it difficult to learn what works and what does not.
3) Some benefits, such as reduced pollution from fossil fuel burning, are difficult to quantify.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3 are true
E) 1 and 3 are true