Answer:
A) No, no lo como para desayuno
Step-by-step explanation:
B has the "los" which is plural so for it to be right the question would have to be ¿Comes cereales para desayuno?
If you answered with C you would be saying "No, I do not eat breakfast", (isnt
gramaticallly correct either).
D has de "la" which is feminine when the word Cereal is masculine. You say El Cereal not La Cereal.
hope this helps