In the following sentence completion question, choose the word that best fits the blank: “As the improvement in his situation was ______________, the doctor did not discharge him.”

Introduction / Context:
This question tests vocabulary and the ability to choose a word that fits both the grammar and meaning of a sentence. The sentence is about a patient's condition and the doctor's decision not to discharge him because the improvement was not good enough.

Given Data / Assumptions:

• Sentence: “As the improvement in his situation was ______________, the doctor did not discharge him.”
• Options: marginal, tiny, microscopic, negated.
• The blank describes the level of improvement in the patient's situation.
• The doctor's decision suggests that the progress was slight or insufficient.

Concept / Approach:
We need an adjective that collocates well with “improvement” and expresses that the change was too small to be considered adequate. While “tiny” and “microscopic” both mean very small, “marginal improvement” is a standard phrase in medical, academic, and general contexts meaning only a slight or minimal positive change. “Negated” would mean cancelled or made zero, which does not fit smoothly as an adjective describing “improvement” in this structure.

Step-by-Step Solution:
Step 1: Understand the logic: because the improvement was not significant, the doctor did not discharge the patient. Step 2: Insert Option A: “marginal”. The sentence becomes “As the improvement in his situation was marginal, the doctor did not discharge him.” This is natural and idiomatic. Step 3: Insert Option B: “tiny”. While the general meaning is similar, the phrase “tiny improvement” is less common in formal reports compared to “marginal improvement”. Step 4: Insert Option C: “microscopic”. This sounds exaggerated and usually refers to things that literally require a microscope, so it is stylistically odd here. Step 5: Insert Option D: “negated”. The phrase “improvement was negated” would require a different sentence structure and suggests that any improvement was cancelled out, not that it was small. It does not fit the given sentence pattern.

Verification / Alternative check:
In medical and technical language, people commonly use “marginal improvement”, “significant improvement”, or “no improvement”. Among the options, “marginal” clearly fits this established pattern. Newspaper health reports and case studies also use this word frequently to signal slight progress, confirming our choice.

Why Other Options Are Wrong:
Option B: “tiny” conveys small size but is more informal and less idiomatic with “improvement” in such a professional context. Option C: “microscopic” overstates the metaphor and is usually used in scientific discussions of very small physical objects. Option D: “negated” functions as a verb participle meaning cancelled; it does not sit well directly after “was” to describe “improvement” in this sentence.

Common Pitfalls:
Students may choose words purely based on similarity of meaning without considering collocation and register. Sentence completion questions are often about choosing the word that native or advanced speakers naturally use with a certain noun. Learning common combinations, such as “marginal improvement”, “substantial loss”, or “gross error”, is helpful for scoring well in such questions.

Final Answer:
The best word to fill the blank is marginal, giving “As the improvement in his situation was marginal, the doctor did not discharge him.”