Why Is Assessment of Level of Conscious (LOC)the Most Important

Why is assessment of level of conscious (LOC) the most important aspect of the neurologic examination?

A) The LOC is the most prognostic indicator of the patient's outcome.
B) The LOC is generally limited to the Glasgow Coma Scale making it the quickest part of the assessment.
C) In most situations the LOC deteriorates before any other neurologic changes are noted.
D) The LOC is the easiest part of the neurologic exam and thus is generally performed first.