The correct answer is: A. a
The word "egg" is a common noun, which means it refers to any egg, not a specific egg. Therefore, we use the indefinite article "a" before it.
The word "an" is used before singular nouns that begin with a vowel sound. The word "egg" begins with a consonant sound, so we do not use "an" before it.
The word "the" is used before specific nouns. In this case, we are not referring to a specific egg, so we do not use "the".
The word "none of the above" is not the correct answer because it is not a noun.
