As oftentimes when nearing death, persons become comatose and$/$or are rendered incapable of meaningfully expressing themselves, having a medical surrogate to act in their behalf permits:

a$.$

A and B

b$.$

Decisions regarding the administration of pain medications to be made

c$.$

Neither A nor B$,$ because the treating physician makes all the decisions regardless

d$.$

Decisions regarding the treatment rendered to them be made