Why Wouldn't You Use Carbon-14 Dating on a Piece of Shell

Multiple Choice

Why wouldn't you use carbon-14 dating on a piece of shell that was estimated to be 1 million years old?

A) Sea shells do not have radioisotopes.
B) Carbon dating is only useful on plants.
C) Uranium dating is better for items older than 1/2 million years.
D) Carbon dating can only be used on items that were once alive.
E) The amount of radioactive carbon in the sample would probably too small to measure.