Improve the bracketed part of the sentence by choosing the most appropriate option: "I prefer black coffee (over) cappuccino."

Introduction / Context:
This sentence improvement question tests knowledge of correct preposition use with the verb prefer. Although several phrases might sound acceptable in casual speech, competitive exams focus on standard and idiomatic usage. The sentence compares two drinks, black coffee and cappuccino, and you must select the preposition or phrase that fits best with prefer in formal English.

Given Data / Assumptions:

- Original sentence: I prefer black coffee (over) cappuccino. - Bracketed word: over, which may need improvement. - Options: rather than, to, instead of, no improvement. - The sentence expresses a general preference, not a single occasion or choice.

Concept / Approach:
In standard English, the usual pattern is prefer A to B when comparing two nouns or noun phrases. For example, one says I prefer tea to coffee or She prefers reading to watching television. While prefer A over B appears in some informal contexts, exams generally consider prefer A to B as the most correct and idiomatic structure. Therefore, the bracketed preposition over must be replaced by to.

Step-by-Step Solution:
Step 1: Identify the basic structure: prefer plus first choice plus preposition plus second choice. Step 2: Recall the standard collocation: prefer A to B. Step 3: Substitute to in place of over: I prefer black coffee to cappuccino. Step 4: Check whether the resulting sentence sounds natural and grammatically correct in formal English, which it does. Step 5: Compare this with the other options, such as prefer black coffee rather than cappuccino or prefer black coffee instead of cappuccino, and note that these patterns are less direct and not the typical textbook construction.

Verification / Alternative check:
Consider parallel examples from reliable grammar sources or exam preparation books. Sentences like Many people prefer saving to spending and I prefer walking to driving follow the same pattern. Replacing to with over in such examples usually makes them less acceptable in formal styled tests. This consistency across examples confirms that to is the best improvement here.

Why Other Options Are Wrong:
Option A, rather than, is often used in a slightly different structure, such as I would rather drink black coffee than cappuccino. Directly following prefer with rather than is possible in some contexts, but the most straightforward and widely taught form is prefer A to B. Option C, instead of, tends to emphasise replacement and sounds less idiomatic directly after prefer. Option D, no improvement, would keep over, which is not the standard answer expected in formal exam English.

Common Pitfalls:
Learners sometimes imitate patterns from spoken English or advertisements where prefer over is used for stylistic reasons. However, standard exam grammar frequently tests the textbook form prefer A to B, and failing to recall this pattern can lead to errors. A useful memory aid is to learn a few fixed examples, such as prefer tea to coffee, and use them as a template whenever you see similar structures.

Final Answer:
to is the correct improvement, giving the sentence I prefer black coffee to cappuccino.