Explanation:

The correct answer is option 'c' - the.

In this sentence, the definite article "the" is used before the noun "beds" to indicate a specific type of beds. The speaker is referring to the beds in a specific hotel, which have been mentioned before or are known to both the speaker and the listener.

Definite Article:
The definite article "the" is used before a noun when the speaker and the listener both know which specific thing or things they are referring to. It is used to refer to something that has already been mentioned or is known to both parties.

Use of "the" in this sentence:
In the given sentence, the speaker is referring to the beds in a specific hotel. The speaker is saying that the beds in that hotel are very uncomfortable. The use of "the" indicates that the speaker is talking about a specific set of beds, which have been mentioned or are known to both the speaker and the listener.

Incorrect options:
- Option 'a' - a: The indefinite article "a" is used before a noun to refer to any one thing of a particular type. It is not suitable in this context because the speaker is referring to a specific set of beds in a particular hotel.
- Option 'b' - an: The indefinite article "an" is used before a noun starting with a vowel sound. It is not suitable in this context because "beds" does not start with a vowel sound.
- Option 'd' - no article: The absence of an article is used before plural and uncountable nouns when making general statements. However, in this sentence, the speaker is referring to a specific set of beds in a particular hotel, so the use of an article is necessary.

Conclusion:
The correct answer is option 'c' - the. The use of "the" before "beds" in the sentence indicates a specific set of beds in a particular hotel.