All of these terms have their own respective official definitions, and they are somewhat similar to the options listed in the question; each one of them matches a listed definition - disregarding the first one.
A symbol is a mark, sign, or word that indicates an idea.
An allegory is a story with a hidden meaning and can be revealed with deep interpretation.
An image is a visual representation of an object or idea.
A universal symbol is a type of symbol that can be recognized visually in all known parts of the planet by humans.
A metaphor is a figure of speech that explicitly states something, but implicitly means something else.
