In the following sentence improvement question, the underlined part is told her teacher: The student told her teacher to explain the passage. Choose the best replacement for the underlined words, or select No improvement if the sentence is already correct.

Introduction / Context:
This question belongs to the sentence improvement type, where a specific part of the sentence is underlined and you must choose a better alternative. The original sentence is The student told her teacher to explain the passage. The underlined part told her teacher is grammatically possible, but it does not express the nuance of a polite request that a student normally makes to a teacher. The objective here is to pick the most appropriate verb that collocates naturally with the situation of asking a teacher to do something.

Given Data / Assumptions:

• Full sentence: The student told her teacher to explain the passage.
• Underlined segment: told her teacher.
• Alternatives: asked her teacher, said to her teacher, conveyed to her teacher, No improvement, requested to her teacher.
• Context: A student wants the teacher to clarify or explain a passage.

Concept / Approach:
In English, we normally use ask when one person wants another person to do something. We say The student asked her teacher to explain the passage, not told her teacher to explain the passage, because tell suggests giving a command rather than making a polite request. The verb ask also correctly takes an indirect object and an infinitive: asked + person + to + verb. Therefore, asked her teacher is the most natural and accurate replacement. Other suggested verbs either lack the sense of request or combine incorrectly with the structure of the sentence.

Step-by-Step Solution:

Verification / Alternative check:
Compare the improved sentence with the original: The student asked her teacher to explain the passage clearly expresses a polite request. It sounds natural in everyday English. If we tried to maintain told, we would normally say The student told her teacher that she did not understand the passage, which is a different structure and a different meaning. Thus asked her teacher is a clear improvement both in usage and in politeness.

Why Other Options Are Wrong:
Option B (said to her teacher) is incorrect in this structure. We usually use say to talk about words spoken, but the normal pattern is said to her teacher that..., not said to her teacher to explain the passage. Option C (conveyed to her teacher) suggests passing on a message, not making a direct request, and the pattern conveyed to her teacher to explain is unnatural. Option D (No improvement) is wrong because told her teacher does not convey the polite-request meaning as well as asked. Option E (requested to her teacher) is grammatically incorrect, because request does not usually take the preposition to before a person; we say requested her teacher or made a request to her teacher, not requested to her teacher.

Common Pitfalls:
Many learners assume that tell and say can always replace ask, but these verbs have different patterns and meanings. Tell often takes a that clause or a direct object and implies giving information or instructions. Ask, on the other hand, is the normal verb when you want someone to do something and works well with infinitive constructions like ask someone to do something. Also, avoid mixing up request patterns; request is more formal and is usually a noun in request for help or a verb followed by an object, not by to before the person.

Final Answer:
The best improvement is asked her teacher, giving the sentence: The student asked her teacher to explain the passage.