Option C clearly states "I may be willing to accept certain medical procedures involving my blood, the details will have to be discussed with me if I am conscious...."

If you'd already decided the treatments you will or won't accept, and communicated in writing to your doctor (or written those on item #4 or item #6 of the DPA card), there would be seem little need for the option C wording. Yet option C exists as a separate choice, so it can't be redundant to the other options.

The wording implies that deferring some treatment decisions is a valid course. If you weren't deferring any decisions, you'd state them in writing on the card or elsewhere, and wouldn't take option C. Unfortunately in a trauma case, this could lead to making decisions when your mental faculties and emotions are compromised, and when you can't calmly and dispassionately study, think and mediate.

Also in a trauma situation you usually aren't treated by your family doctor, but by a trauma center you may have never previously interacted with. In that case you'd have had no prior opportunity to communicate your wishes -- what you write on the DPA card could be the only treatment guidelines they have. If you select only option C, that means they have no guidelines at all about treatment involving minor blood fractions. They'll have to discuss it with you in the heat of the moment.

My point is it's important to make specific informed choices beforehand, not defer those decisions until you're possibly suffering from trauma or influenced by analgesics.