. . . . . . . . great improvement in . . . . . . . . patients condition was brought about by . . . . . . . . use of . . . . . . . . newly developed antibiotic. A. no article, the, no article, a B. a, the, no article, no article C. the, the, no article, no article D. a, the, the, a

The correct answer is: A. no article, the, no article, a

The article “a” is used before singular nouns that refer to something that is not specific or particular. In this case, the patient’s condition is not specific, so the article “a” is used.

The article “the” is used before singular nouns that refer to something that is specific or particular. In this case, the antibiotic is specific, so the article “the” is used.

No article is used before plural nouns. In this case, the use of the antibiotic is not specific, so no article is used.

Here is a more detailed explanation of each option:

• Option A: no article, the, no article, a
  This option is correct because it uses the appropriate articles for each noun. The article “a” is used before singular nouns that refer to something that is not specific or particular. In this case, the patient’s condition is not specific, so the article “a” is used. The article “the” is used before singular nouns that refer to something that is specific or particular. In this case, the antibiotic is specific, so the article “the” is used. No article is used before plural nouns. In this case, the use of the antibiotic is not specific, so no article is used.
• Option B: a, the, no article, no article
  This option is incorrect because it uses the article “a” before the noun “patient.” The article “a” is used before singular nouns that refer to something that is not specific or particular. In this case, the patient is specific, so the article “the” should be used instead.
• Option C: the, the, no article, no article
  This option is incorrect because it uses the article “the” before the noun “use.” The article “the” is used before singular nouns that refer to something that is specific or particular. In this case, the use of the antibiotic is not specific, so no article should be used instead.
• Option D: a, the, the, a
  This option is incorrect because it uses the article “a” before the noun “antibiotic.” The article “a” is used before singular nouns that refer to something that is not specific or particular. In this case, the antibiotic is specific, so the article “the” should be used instead.