The trend in excess bank reserves in the US is:

A.

Banks historically kept a minimum amount of excess reserves but then started piling up excess reserves after the 2008 financial crisis

B.

Historically, excess bank reserves is closely tied to how fast the economy is growing and they share a similar trend as GDP

C.

Historically, excess reserves are closely tied to the interest rates and increase as the interest rates fall

D.

Banks historically kepts a cushion of excess reserves but then in the 2008 crisis this wiped those out and now they keep much lower levels of excess reserves