What are the indications and contraindications for the ketogenic diet?

The ketogenic diet is the first-line treatment for two diseases that affect cerebral energy metabolism, with or without epilepsy: cerebral glucose transporter type 1 deficiency syndrome (GLUT1) and pyruvate dehydrogenase deficiency.
The ketogenic diet has traditionally been considered a last resort in the treatment of refractory epilepsy in children, due to the lack of studies demonstrating its efficacy and the concern that it would not cover the nutritional needs for adequate growth.
The ketogenic diet is potentially effective in any form of refractory epilepsy, and some examples in which there is evidence of its efficacy include West syndrome, Dravet syndrome, Landau-Kleffner syndrome, and epilepsy associated with tuberous sclerosis or Rett syndrome.
The ketogenic diet is contraindicated in patients with primary carnitine deficiency, carnitine palmitoyltransferase I or II deficiency, translocase carnitine deficiency, beta-oxidation defects, pyruvate carboxylase deficiency, and porphyria.
a) Only statements I and II are correct.
b) Only statements II and III are correct.
c) Only statements III and IV are correct.
d) All statements are correct.