The correct answer is: B. absolutely no worry
The other options are incorrect because they do not convey the same level of certainty as the correct answer. Option A, “no absolutely worry,” is too vague. It is not clear whether the speaker is saying that there is no worry at all, or that there is some worry but it is not absolute. Option C, “absolutely not worrying,” is also too vague. It is not clear whether the speaker is saying that they are not worried at all, or that they are trying not to worry. Option D, “No improvement,” is not an option because it does not answer the question.
The correct answer, “absolutely no worry,” is the most concise and direct way to convey the speaker’s certainty that there is no need to worry.