T because i really think its the answer i am not really sure but im going for it....
Answer:
its easier
Explanation:
the human figure (or some animals) are very complex figures , making them is hard enough plus you have to have a lot of clay etc. but to make a pose is much more difficult because there is so much detail
There were actually several building techniques that were introduced by the Romans, but perhaps the most important was the bridge building technique that allowed bridges to be built without supports.