Answer:
the answer to your question is c
That's true. The give-away is "observation ... in the real world". That's what "field reports" are.
The part I'm not so sure about is those "entific findings".
A sound wave is a longitudinal wave
I think it occurs whenever waves come together so that they are in phase with each other.
Answer:
This has all the answer (Data sheet, graph, answers to the questions, and the summary) :)