Improve the bracketed part of the sentence by choosing the correct option. If no improvement is required, select "No improvement". Sentence: The Centre cannot afford to procrastinate any further (at) framing rules to regulate the trading and use of bitcoin and other virtual currencies.

Introduction / Context:
This sentence improvement question examines your understanding of which prepositions combine naturally with the verb procrastinate. The sentence talks about delay in framing rules to regulate bitcoin and other virtual currencies. The bracketed preposition at must be evaluated to see whether it is idiomatic or whether a different preposition is normally used after procrastinate in modern English.

Given Data / Assumptions:

• The sentence is: The Centre cannot afford to procrastinate any further at framing rules to regulate the trading and use of bitcoin and other virtual currencies.
• The bracketed preposition is at.
• Options: on, under, of, No improvement.
• We assume the intended meaning is that the Centre must not delay any longer in the task of framing rules.

Concept / Approach:
In natural English, people procrastinate over or on a task, idea or decision. Procrastinate at is not a standard collocation. Therefore, the correct preposition should be on in this context: procrastinate on framing rules. Under and of do not fit the pattern either. So replacing at with on gives a smooth and idiomatic sentence that conveys the intended meaning clearly.

Step-by-Step Solution:
Step 1: Isolate the key verb phrase: procrastinate any further plus preposition plus gerund framing rules.Step 2: Recall that we commonly say procrastinate on doing something or procrastinate over doing something.Step 3: Recognise that at sounds unnatural after procrastinate and is not used in standard exam level English.Step 4: Substitute on in place of at and read the sentence: The Centre cannot afford to procrastinate any further on framing rules to regulate the trading and use of bitcoin and other virtual currencies. This now feels natural and correct.Step 5: Check under and of and observe that procrastinate under or procrastinate of framing rules has no recognised idiomatic use. Therefore, on is the only option that improves the sentence.

Verification / Alternative check:
Compare with similar structures: Many students procrastinate on starting their assignments, and The committee has procrastinated on making a final decision. In each case, on introduces the task or decision being delayed. Using at, under, or of would make these sentences sound incorrect. Because framing rules is exactly the sort of task one can procrastinate on, the same preposition should be used here.

Why Other Options Are Wrong:
Under is generally used with nouns like investigation or pressure and not with procrastinate. Of typically marks possession or relation and does not follow procrastinate when introducing an activity. No improvement would keep the non standard at framing rules, which is not how native speakers express this idea in formal writing. Therefore, all other options fail to capture the verb preposition pattern correctly.

Common Pitfalls:
Preposition choice is often influenced by the learner first language, leading to direct translations that do not match English collocations. A reliable way to improve in this area is to read editorial style articles and notice which prepositions consistently follow common verbs like depend, insist, and procrastinate. Building a mental list of these combinations will make questions like this much easier.

Final Answer:
The correct improvement is to replace at with on, so option A is correct.