I want to know the answer to the following question:
What declined from the 5th to the 13th centuries
All the background I'm provided with is that "From the fifth century to the thirteenth, Śrauta sacrifices declined, and initiatory traditions of Buddhism, Jainism or more commonly Shaivism, Vaishnavism and Shaktism expanded in royal courts.". Is that enough to answer the question?
Answer: yes