This is a question with answer options. What kind of thing would the answer to the question "What President was meant for , but never placed in , the empty crypt beneath the capital 's rotunda ?" be an entity, an abbreviation, a description, a human, a location, or a numeric value?

Available options:
(a). description.
(b). entity.
(c). abbreviation.
(d). human.
(e). numeric.
(f). location.
(d).