Choose the option that best expresses the meaning of the English idiom "by fits and starts" as used in standard usage.

Introduction / Context:
The idiom by fits and starts is commonly used in English to describe how an activity is carried out over time. Many idiom questions in competitive examinations focus on time related expressions, because they often cause confusion for learners. Understanding this idiom helps you describe patterns of work, study, or effort that are not steady or consistent.

Given Data / Assumptions:

• The idiom is by fits and starts.
• It refers to the manner or pattern in which something happens over a period of time.
• We are choosing the closest meaning among four alternatives.
• The correct meaning is about irregularity, not completeness or frequency alone.

Concept / Approach:
By fits and starts describes an action that happens in sudden bursts of activity followed by periods of little or no activity. In other words, the effort is irregular and lacks steady progress. For example, if someone studies by fits and starts, they may work intensely for a short time, then stop completely, then start again later. The idiom does not mean that something is totally completed, nor that it happens constantly without break. It also does not simply mean eventually; it highlights the stop and go nature of the process.

Step-by-Step Solution:
Step 1: Recall that fits can mean sudden bursts or attacks, and starts suggests sudden beginnings. Step 2: Put these ideas together: repeated sudden beginnings separated by pauses indicate irregular progress. Step 3: Examine the options and look for a phrase that captures this stop and go pattern. Step 4: Option A, at irregular intervals and without steady progress, matches this meaning exactly. Step 5: Recognise that the other options talk about being completely finished, taking a long time, or being constant, which are all different ideas.

Verification / Alternative check:
Consider the sentence: He wrote the novel by fits and starts over five years. This suggests that his writing was not continuous; instead, he wrote for short periods and then stopped, repeating the cycle. If we replace the idiom with at irregular intervals and without steady progress, the sentence keeps the same sense: He wrote the novel at irregular intervals and without steady progress over five years. None of the other options produce the same meaning when substituted into the sentence, confirming Option A as correct.

Why Other Options Are Wrong:
Completely and totally finished: This is wrong because by fits and starts does not describe completion; it describes the manner in which work is done on the way to completion, often slowly and unevenly.
Eventually, after a long time: This is wrong because the idiom is not about final timing; it is about the pattern of interruptions and bursts before the final result, which may or may not take a long time.
Very frequently and continuously: This is wrong because continuous activity is the opposite of the stop and go irregularity implied by fits and starts.

Common Pitfalls:
Students often confuse by fits and starts with once and for all or at last, believing it relates to the final moment when something is done. Others think it describes frequent activity because of the word fits. To avoid these mistakes, focus on the idea of repeated, sudden beginnings and stopping. Any idiom that refers to bursts of effort with gaps in between is likely talking about irregular progress rather than constant or total activity.

Final Answer:
The idiom by fits and starts means At irregular intervals and without steady progress.