Refer to the exhibit.

In the exhibit, a correlogram is provided based on an autocorrelation analysis of a sample dataset.
What can you conclude from only this exhibit?

A.
There is significant autocorrelation through lag 3

B.
There is no structure left to model in the data

C.
Lag 7 has a significant negative autocorrelation

D.
Differencing is required before proceeding with any analysis