Apple - Why is Apple hardware test (AHT) not loading when pressing key D on system start?

Pressing ⌥+D right after pressing the power button and before the gray screen appears works on my late-2011 15" MBP. This forces an internet-based hardware test, which will work even if you've lost the the local hardware test software. (It will probably work over WiFi, but you have more chance of success with ethernet.)

Same thing here (similar model MBP, same mods). Learned that Option+D does the trick. However, if you get what I see, the AHT fires up and then says that it doesn't support this model of machine. No funny business, it's an Apple MBP (no hackintosh here), but I added a OCZ Vertex 3 and I've tried pre-8GB RAM kit (stock) and post, no difference.

Its Option + D that works for me. Macbook Pro, Late 2011 model running Mavericks.