In the following idiom and phrase question, choose the alternative that best expresses the meaning of the expression "Once and for all."

Introduction / Context:
This idiom question focuses on the phrase "once and for all," a common expression in English used when someone wants to settle a matter completely and finally. The idiom describes an action that is intended to be decisive, leaving no need for repetition or further argument. You must select the option that best captures this "final and definite" sense.

Given Data / Assumptions:

• Idiom: "Once and for all."
• Common usage: resolving a dispute, making a final decision, or ending uncertainty.
• Options include meanings related to success, charity, and speaking for others.
• The correct answer should highlight finality and the idea of not having to do something again.

Concept / Approach:
"Once and for all" means doing something now in such a complete and decisive way that it will not have to be repeated. For example, "Let us settle this question once and for all" means "Let us settle it finally, for the last time." The phrase does not specifically refer to success on the first attempt or to charitable acts; rather, it emphasises final resolution. Therefore, the option that describes "now and for the last time; finally" is the best match.

Step-by-Step Solution:
Step 1: Recall typical sentences: "I will tell you once and for all that I am not coming," or "This will decide the issue once and for all." Step 2: Recognise that in each case the speaker wants to end argument or doubt permanently. Step 3: Look at the answer choices and find the one that mentions finality and last time. Step 4: Option A states "Now and for the last time; finally," which exactly matches the idiom's meaning. Step 5: Choose option A and disregard options that introduce unrelated ideas like charity or representation.

Verification / Alternative check:
Try substituting each meaning into a typical sentence: "Let us settle this once and for all" becomes "Let us settle this now and for the last time; finally," which works well. It does not mean "let us be successful in the first attempt" or "let us do a charitable act." Nor does it mean "to speak for the majority." These alternatives either change the focus or add new concepts not implied by the idiom. This confirms that option A correctly expresses the intended meaning.

Why Other Options Are Wrong:

• To be successful in the first attempt: Being successful at first try is not the core idea; "once and for all" can involve many attempts previously but a final decisive action now.
• To do a charitable act for the benefit of everybody: Introduces the idea of charity, which has nothing to do with the idiom.
• To speak for the majority: Refers to representation or majority opinion, unrelated to final resolution or last time.

Common Pitfalls:
Some test takers focus on the word "once" and link it to "first attempt," but the full idiom "once and for all" is about finality, not about first try. Idioms must always be interpreted as fixed expressions, not as separate words. When you see "and for all," think of "for all time" or "forever," which helps you remember the sense of final decision.

Final Answer:
The idiom "Once and for all" means now and for the last time; finally.