Answer :
The correct answer is a) - many traditions grew out of it. It was a time of great wealth, which contributed greatly to the development of art and architecture.
I believe the answer is: A.many southwest Asian traditions grew out of that culture
In the past, Khmer empire control a large portion of South East Asian territories. Since at that time South East Asia control the trade routes in all South Asia, the cultures and traditions that introduced by Khmer Culture was spread almost to all South Asian region.