Answer:
The correct option is a. (Esta comida es mía, y esa es tuya)
Step-by-step explanation:
About the option b and c.
The word "eso" is a demonstrative pronoun and is misused in the sentence, since it is written in a masculine way and "comida" is a word that is used in feminine. (La/esa comida). In the same way happens with option c, "aquello" is a word well used in that type of sentence, but the genre is not. Aquello refers to a masculine noun, and aquella refers to a feminine noun / word, such as: comida.