1. What is the English word for Gungjeon?

2. It is palace.
3. It is a palace.
4. It is 'palace'.
5. It is 'palace.'

[Which answer is grammatical?]

It is"palace".

Out of the given answers, answer 3, "It is a palace," is the grammatically correct option.

In English, a sentence typically begins with a capital letter and ends with punctuation. In this case, "palace" is a common noun, and when referring to something in a general sense, it is appropriate to include the article "a" before the noun. Therefore, answer 3, which includes the article "a" before the word "palace," is the correct answer.

Answers 2 and 4 are close, but they lack the article "a" before "palace," resulting in incomplete sentences. Answer 1, "What is the English word for Gungjeon?," is a question and doesn't directly answer the original question. Answer 5, "It is 'palace.'", includes unnecessary quotation marks around the word "palace," which is not the standard convention in English grammar.