Yes, but be it will be a VCDX4 defense. Also be prepared to answer any question on vSphere 4.x or vSphere 5.x. That's what I did. I don't think there are many VCDX4 defenses left, so sign up soon. Assuming you pass, then your a VCDX4, and can upgrade that to VCDX5 after you pass the VCAP5-DCD exam.
The big issue is that you haven't a defense session for VCDX4:
No new date are available.
For VCDX5 the first available session is PEX