Answer:
C. Metaphor
Explanation:
Let's go through each answer together.
A. Personification: Personification is when an inanimate object is given human quialities, or does human things. (Do you see the word <em>person </em>in personification?) For example, if I said my pencil was running away from me, it would be personification. A pencil can't actually run! But I'm sure you understood what I was describing anyways. Heaven is not a uhman quality, so it isn't personification.
B. Hyperbole: A hyperbole is when you exaggerate something. So, if I said that my the dog was 10 feet tall, I would be using a hyperbole. We both know the dog couldn't actually have been 10 feet tall. But, you understood that the dog must have been huge. We don't do this with the cake!
C. Metaphor: It's easy to get confused between metaphors and similes. A metaphor is when we say object A IS object B. For example, The sky was an endless pool. A sky can't actually be a pool, but we're saying that it is anyways. We want to make a point! This is what is happening in the question. A cake can't <em>actually</em> be heaven, but now we see that the cake must have been extremely good.
D. Simile: A simile is like the metaphor's sister. They're very similar, but similes are different in this specific way. ALL similes use either "like" or "as". For example, the house was like a fire. We're not saying the house is actually a fire, we're saying that it was LIKE a fire. They're both hot! To find similes, make sure to look for "like" or "as"- our example sentence has neither.
Hope this helps & feel free to ask for any clarification!