Someone who "eats like a ..." is someone who eats a lot or has a huge appetite

There was this Chinese TV quiz show and one question was a multiple choice question about English sayings/idioms. It went something like this:

In the English idiom, someone who "eats like a [fill in the blank]" is someone who eats a lot or has a huge appetite:

(a) King (b) Mouse (c) Horse (d) Dog

I didn't think any of the four possible choices constituted an English idiom. Is one of the above four choices even an answer to the question? And if so, which is it?

Added information: The answer given in the game show was indeed "Horse". I was surprised because I have never in my life heard anyone use the expression "eat like a horse", although I have heard "eat like a king" (albeit only on a few occasions). Also I've seen dogs and horses eating, and it seems that horses eat in a calm, reasonably slow pace, whereas dogs always eat like they've been starving for days. Hence, "eat like a horse" made no sense to me at all.

Eat like a horse historically speaking: (from Idoomation.wordexpress)

• If someone says that you eat like a horse, it mean you are eating, or have eaten, a lot of food. In some instances this is a compliment while in others it’s an insult. It all depends on the situation and the people involved. Interestingly enough, in French the expression is “manger comme un ogre” (translation: eat like an ogre) or “manger comme quatre” (translation: eat as if one was four)

• The Baltimore Sun ran an article on December 28, 1952 entitled, “Add One Elephant > To The Holiday Toll.”

  • A person may be as hungry as a bear and may eat like a horse but there are definite limits beyond that.

• Thee Pittsburgh Press ran an advertisement espousing the benefits of The Reese Formula R-11 in its August 9, 1920 edition.

  • I can eat like a horse, sleep like a country boy and feel like a 16-year old boy. If you wish to sue my name you are at liberty

• Back on July 12, 1882 the St. Joseph Daily Gazette in St. Joseph, Missouri published an article on Tug Wilson, the English pugilist.

  • He can now skip about like a squirrel, eat like a horse, and move about like a champion pugilist.

• Idiomation was unable to find an earlier published version of this expression however there appears to be a jump between the expression “work like a horse” and “eat like a horse.” The former expression dates back to at least 1520 when horses replaced oxen and began to pull carts, wagons, carriages, chariots and sleighs.

Yeah, the proper answer to their question is most certainly "horse". Someone who "eats like a horse" can put away a lot of food. Someone who "eats like a pig" is poorly mannered while eating, making a mess and resembling a pig feeding at a trough. To "eat like a king" means to have the highest quality and/or quantity of food available to choose to eat, like a "King's feast". Someone who "eats like a bird" is the exact opposite of someone who "eats like a horse" in that they barely eat any food, as if they are pecking at it like a bird. I've also heard the term "eats like a mule" used to mean the same thing as horse. Hope this helps.

To eat like a horse is to always eat a lot of food.