So the best i could find was in First Aid 2019 pg 346 under Diabetic Ketoacidosis. The hyperglycemia and hyperkalemia cause an osmotic diuresis so the entire body gets depleted of fluids. Hence why part of the treatment for DKA is IV fluids. You might even rely on that piece of information alone to answer this question, that DKA is treated with IV fluids.

GLUT3 is in the brain/neurons. If there is glucose, the brain will be able to use it.

Only GLUT4 is insulin-dependent, seen in muscle and fat.

https://step1.medbullets.com/biochemistry/102017/glucose-transport

Big Robbins:

https://i.imgur.com/gQnDH92.png

Idk how you could say that it's from extracellular dehydration, but whatever I guess.

this is how I looked at it extra cellular osmoles> intracellular so it will pull the h20 out.... then the high osmotic pull of the sugar overwhelming the SGL2 transporter in the kidney will pull the h20 out of the body dehydrating the extracellular compartment

What i think it is that, ECF osmolarity is increased, draws water and K out of cell --> intracellular dehydration Osmotic diuresis in the kidneys, loss of glucose and water in kidneys --> Extracellular dehydration

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2909073/

says that hyperosmolarity and acidosis alter mental status.

which correlates with the right answer

p.s i got it wrong too :)

a little messed up, but "Inability of neurons to perform glycolysis" seems like a tempting answer. But the reality is, the neurons are able to perform glycolysis, they ready to rock but just waiting on insulin. I still chose this as my answer tho.

I guess this is one of those choose the best answer questions. I think FA should add the reasoning behind cerebral edema, being that it's a major cause of death (but I couldn't find it in Robbins either). Having so much glucose in the blood vessels causes water to be drawn out (ICF --> ECF). So that's a intracellular dehydration.