Please help with 2007 Macro FRQ!

Test Preparation AP Test Preparation
1

<p>[url=<a href=“2007 Macro FRQ | PDF | Demand For Money | Interest”>2007 Macro FRQ | PDF | Demand For Money | Interest]2007%20Macro%20FRQ[/url</a>]</p>

<p>On slide 5, part (C), what does DD, ER, M, and Mm stand for?</p>

<p>TIA!</p>