In the following idiom and phrase question, select the option that best expresses the meaning of the word "Scapegoat".

Introduction / Context:
This idiom question focuses on the word scapegoat, which has a specific figurative meaning in modern English. While the word has religious and historical origins, in everyday usage it refers to a person who is unfairly blamed for problems or failures that are actually the responsibility of others. Understanding this meaning helps in reading news reports, office stories, and political commentary.

Given Data / Assumptions:

- Target word: Scapegoat. - Options describe various possible roles of a person or animal. - The correct option must match the modern idiomatic meaning.

Concept / Approach:
In present day usage, a scapegoat is a person who is made to bear the blame for the wrongdoings, mistakes, or faults of others, often to protect more powerful or guilty individuals. This sense developed from an older religious ritual, but in exams the focus is on the general meaning, not the ritual itself. The correct option is the one that explicitly states that someone is blamed for the mistakes of others.

Step-by-Step Solution:
Step 1: Recall common usage, such as The intern became the scapegoat for the management's poor decisions. Step 2: Read option D: A person who is blamed for the mistakes of others. This matches the remembered usage exactly. Step 3: Examine option A, which refers to an animal sacrifice as an offering to God. This describes a religious ritual but not the modern everyday idiom. Step 4: Consider option B, the most useful animal or person. This has a positive sense and does not involve blame. Step 5: Check option C, a lucky person who is forgiven for his crimes, which again misinterprets the idea, focusing on forgiveness rather than unjust blame. Step 6: Conclude that option D is the only one consistent with contemporary idiomatic meaning.

Verification / Alternative check:
Try replacing scapegoat with each option in a typical sentence, for example, In the scandal, the junior officer was used as a scapegoat. If we replace it with option D, we get The junior officer was used as a person who is blamed for the mistakes of others, which preserves the sense. Using options A, B, or C leads to either religious or positive interpretations that do not match the original, confirming that they are incorrect.

Why Other Options Are Wrong:
Option A refers to historical practice but does not represent the way the word is normally used in everyday English now. Option B imagines a most useful person or animal, which contradicts the negative and unfair nature of blame in scapegoating. Option C mentions forgiveness and luck, which again miss the central idea of unjustly taking the blame for others.

Common Pitfalls:
Some candidates are distracted by the original religious meaning or assume that questions with animal related words must be about literal animals. It is important in idiom questions to focus on current figurative meanings, which are revealed by how the word appears in newspapers and conversation. Remembering a few examples of scapegoat being used to describe unfair blame will stop you from choosing answers that only hint at its historical origin.

Final Answer:
A person who is blamed for the mistakes of others is the correct meaning of scapegoat in modern English.