In the following sentence improvement question, choose the alternative that best completes the sentence using the correct form of the verb in brackets. In case no improvement is needed, select "no improvement": "The tropical storm (be) a hurricane."

Introduction / Context:
This question examines your understanding of verb tense and correct infinitive or finite verb usage in a predictive sentence about weather. The sentence describes a tropical storm that is expected to intensify into a hurricane. The verb in brackets "(be)" needs to be replaced with a suitable form that clearly expresses this future change, in line with standard English usage.

Given Data / Assumptions:

• Base sentence: "The tropical storm (be) a hurricane."
• The context is meteorological prediction or forecast.
• The intended meaning is that the storm is expected to become a hurricane in the future.
• Options include "will become," "become," "to become," and "no improvement."

Concept / Approach:
In English, when predicting that one state will change into another in the future, we commonly use "will become": "The child will become an adult," "The drizzle will become heavy rain." Similarly, for storms, weather forecasts say, "The tropical storm will become a hurricane" to indicate future intensification. The bare form "become" without an auxiliary is incomplete, and "to become" is an infinitive that does not fit as the main verb in this independent clause. Therefore, a future tense construction with "will become" is required.

Step-by-Step Solution:
Step 1: Decide on the time reference: the change from storm to hurricane is in the future. Step 2: Use the auxiliary "will" to form the simple future tense. Step 3: Combine "will" with the base verb "become" to make "will become." Step 4: Insert this into the sentence: "The tropical storm will become a hurricane." Step 5: Confirm that the sentence now conveys a clear prediction in correct tense and form.

Verification / Alternative check:
Test the other options: "The tropical storm become a hurricane" lacks an auxiliary and is grammatically incorrect in standard English. "The tropical storm to become a hurricane" is also wrong, because an infinitive cannot serve as the main verb without a helping verb. "No improvement" would leave "(be)" unresolved, which is not acceptable. In weather reports, standard phrasing is indeed "will become a hurricane," confirming that option A is correct.

Why Other Options Are Wrong:

• Become: Missing auxiliary; we cannot say "The storm become a hurricane" in simple declarative English.
• to become: Infinitive form, which cannot function as the main finite verb of this sentence without an auxiliary.
• no improvement: Leaves an incomplete structure "(be)," which is not a finished sentence.

Common Pitfalls:
Learners sometimes forget that English requires an auxiliary verb for future tense predictions and may incorrectly place a bare infinitive after a subject. Another frequent issue is misinterpreting the bracketed base form "(be)" as a signal to use the plain form "become," ignoring tense. In exam questions, always consider the time reference implied by the context and choose a complete, finite verb form that fits it, especially in sentences about forecasts or planned changes.

Final Answer:
The correct improvement is will become, giving the sentence: The tropical storm will become a hurricane.