The correct answer is: A. a, the
The article “a” is used before singular nouns that refer to a general class of things. In this case, the noun is “horror film”. A horror film is a general class of films that are typically characterized by suspense, violence, and fear.
The article “the” is used before singular nouns that refer to a specific thing or person. In this case, the noun is “TV tonight”. TV tonight is a specific time and place where the horror film will be shown.
The other options are incorrect because they do not use the correct article for the noun in the sentence. Option B, “an, no article”, is incorrect because the article “an” is used before singular nouns that begin with a vowel sound. The word “horror” begins with a consonant sound, so the article “a” should be used instead. Option C, “no article, no article”, is incorrect because the article “a” or “the” is required before the noun “TV tonight”. Option D, “a, no article”, is incorrect because the article “a” is used before singular nouns that refer to a general class of things, while the noun “TV tonight” refers to a specific time and place.