Correct option is D
The correct question tag for the sentence "The hotel is expensive" is "isn't it?".
So the complete sentence with the question tag would be:
"The hotel is expensive, isn't it?"
The sentence "The hotel is expensive" is a positive statement.
To form the question tag, we use the negative form of the verb "is" (which is "isn't") and the pronoun "it" to refer back to "the hotel".