A part of the sentence is underlined. Choose the alternative that best improves the underlined part. If no improvement is needed, select the option indicating no improvement. A black and white goat were grazing.

Introduction / Context:

This question focuses on correct use of articles and subject verb agreement when describing more than one noun with adjectives. The original sentence suggests that two goats of different colours were grazing. However, the phrase A black and white goat can be interpreted as a single goat that is both black and white, which creates confusion with the plural verb were. The improvement must make it clear that there are two goats and keep the verb in agreement.

Given Data / Assumptions:

• Original sentence: A black and white goat were grazing.
• The underlined part is A black and white goat.
• Options include phrases with different combinations of articles and adjectives, plus no improvement.
• We assume that the intention is to speak about one black goat and one white goat together.

Concept / Approach:

When two different nouns or two individuals of the same type are described with adjectives, articles help signal whether you are talking about one combined item or two separate items. A black and white goat usually means one goat that has both colours. If you want to refer to two goats, one black and one white, you should repeat the article before each adjective and use a plural verb. Therefore we need a phrase like a black and a white goat with the plural sense.

Step-by-Step Solution:

Verification / Alternative check:

Rewrite the full improved sentence: A black and a white goat were grazing. Now it clearly indicates two goats and keeps the plural verb correct. If we used the original phrase with one article, we would have to change the verb to was to maintain agreement. Since the question only allows change in the underlined part, the option that salves the agreement problem while keeping were is the one that marks the subject as plural.

Why Other Options Are Wrong:

The white and the black goat is awkward and focuses on one white and one black goat, but it still suggests two goats and could work only if the entire sentence is rewritten for style.

Black and a white goat lacks an article before black, which makes the noun phrase incorrect.

No improvement is wrong because the original phrase with a single article and plural verb is inconsistent and confusing.

Common Pitfalls:

Many learners overlook the subtle change in meaning when the article is repeated. Another pitfall is to ignore the verb and focus only on the noun phrase. In subject verb agreement questions, always check how changing the subject affects the verb selection and whether the number remains consistent throughout the sentence.

Final Answer:

The best improvement is A black and a white goat.