In the following passage, choose the correct verb form to complete the sentence: "The scenario _________________ dramatically today."

Introduction / Context:
This cloze passage question requires you to select the correct verb form in a sentence that describes how a situation is different now compared with the past. The time marker today is important because it signals a present time frame and often goes with the present perfect tense when highlighting change up to the present moment.

Given Data / Assumptions:

- Sentence fragment: The scenario _________________ dramatically today. - Options: change, had changed, has changed, changing. - The passage goes on to discuss the current presence of powerful Internet monopolies. - The writer wants to emphasise the change that has occurred up to the current time.

Concept / Approach:
When we talk about change that has taken place up to now and is relevant to the present, English frequently uses the present perfect tense, formed with has or have plus past participle. The phrase has changed dramatically today fits this pattern: it conveys that the scenario is no longer what it used to be and that the change is linked with today's conditions. Simple past or past perfect would focus on a completed event at a specific time in the past, which does not match the continuous influence suggested by today in this context.

Step-by-Step Solution:
Step 1: Identify the subject, the scenario, and the time reference today. Step 2: Recall that present perfect, has changed, is often used when describing changes that influence the present situation. Step 3: Insert has changed into the sentence: The scenario has changed dramatically today. Step 4: Evaluate the other options. Change without an auxiliary is incorrect here, as the sentence needs a finite verb. Step 5: Had changed is past perfect, which normally requires a second past reference point and does not fit well with today. Step 6: Changing is a present participle, which would require an auxiliary to form a correct verb phrase and therefore cannot stand alone.

Verification / Alternative check:
Read the sentence in the context of the complete passage: The scenario has changed dramatically today. We have the emergence of powerful Internet monopolies... The combination of present perfect in the first sentence and present tense in the second supports the idea that the writer is describing the world as it now stands, having gone through notable change. If we used had changed, it would sound as if the change occurred before another past moment, which is not provided.

Why Other Options Are Wrong:
Option A, change, would require a third person singular auxiliary such as does in simple present or will in simple future; on its own it cannot complete the sentence. Option B, had changed, is the past perfect and is usually paired with another past event, as in The scenario had changed before we noticed, which is not the case here. Option D, changing, functions as a participle or gerund and cannot serve as the main verb without an auxiliary like is or was.

Common Pitfalls:
Some learners automatically select simple past forms or past perfect forms whenever they see an adverb related to time. However, in sentences focusing on present consequences or current state, the present perfect is more appropriate. A useful guideline is that when you describe how something is different now compared with before and use words like today, in recent years, or lately, has or have plus past participle is often the best choice.

Final Answer:
has changed correctly completes the sentence The scenario has changed dramatically today.