Marcie, 85 years old, recently recovered from hip surgery and resumed bicycling. She is struck by a texting driver, is thrown off her bike, and hits her head on a concrete curb. She is now unresponsive with no brainstem reflexes. She is a registered organ donor.

The family asks, "Why is she considered dead if her heart is still beating? What is the best response?

"We must wait until her heart stops to declare death."

"Brain death is legal death because the brain can no longer sustain life or recover."

"Her heart will stop soon."

"Brain death means she is in a very deep coma."