An Elderly Woman Found with a Head Injury on the Floor

An elderly woman found with a head injury on the floor of her home is subsequently admitted to the neurologic ICU. What is the best rationale for the following physician orders: elevate the HOB; keep the head in neutral alignment with no neck flexion or head rotation; avoid sharp hip flexion?

A) To decrease cerebral arterial pressure
B) To avoid impeding venous outflow
C) To prevent flexion contractures
D) To prevent aspiration of stomach contents