I think it's D. Their music was kept simple. Hope this helps!
Provide information or evidence
It gives you visual proof that someone agreed to something, so that, later on, they can't say they didn't agree to that. It's like when you sign a contract, it is proof of the agreement.
Answer: At an astronomical rate the impact ,it has doubled in size sice the 1960s
All of the above is the answer.
