Answer:
The correct verbal conjugation is:
Me gustó.
Step-by-step explanation:
The whole phrase has a past tense expressed, because it has the verb "comer" conjugated as "comí"
That is why when a person refers to "comí" you can expect that the next part of the sentence is also in the past form.
It cannot be "me gustaba" because it is the first time the person tastes the food.
It can't be "me gusta", because starting a sentence in the past and then answering it in the present is wrong.