Choose the option that best expresses the meaning of the English idiom "caught red-handed".

Introduction / Context:
This question tests your understanding of a common English idiom, caught red-handed. Idioms are fixed expressions whose meaning cannot be understood simply by translating each word literally. In competitive exams, idioms are often asked because they reflect natural usage and cultural familiarity with the language.

Given Data / Assumptions:
We are given the idiom:

• caught red-handed

The options are:

• Caught by mistake
• Caught with a red handkerchief
• Found wounded
• Discovered in the act of doing wrong

Concept / Approach:
The idiom caught red-handed means to be caught in the very act of committing a crime, offence, or wrong action, with clear evidence that cannot be denied. Historically, it suggests hands literally stained with blood, but in modern usage it covers any wrongdoing, such as stealing, cheating, or lying. The correct option must capture this idea of being discovered while the wrongful act is actually taking place.

Step-by-Step Solution:
Step 1: Focus on the key word caught, which indicates that someone is being discovered while doing something. Step 2: Note that red-handed is not meant literally in most contexts. It symbolises clear evidence of guilt. Step 3: Evaluate Caught by mistake. This only suggests an accidental catching and does not include any idea of wrongdoing. Step 4: Evaluate Caught with a red handkerchief. This is a literal and irrelevant interpretation of red-handed. Step 5: Evaluate Found wounded. This suggests injury but nothing about committing an offence. Step 6: Evaluate Discovered in the act of doing wrong. This option clearly captures the idiomatic meaning of being caught while committing an offence or misdeed, with proof of guilt. Step 7: Therefore, Discovered in the act of doing wrong is the correct explanation of the idiom.

Verification / Alternative check:
Consider common usage: The thief was caught red-handed while stealing a wallet. This clearly means that the thief was discovered at the very moment of stealing, not after the fact. If the expression meant caught by mistake, the sentence would not emphasise guilt. Similarly, caught red-handed while copying in an exam describes a student seen actually cheating. Such examples support the chosen meaning.

Why Other Options Are Wrong:
Caught by mistake is wrong because caught red-handed emphasises definite guilt, not accidental capture. Caught with a red handkerchief is wrong because it translates the phrase literally, which is not how idioms work. Found wounded is wrong because it refers to physical injury, which is unrelated to the idea of wrongdoing. None of these options express the notion of being discovered during a wrongful act.

Common Pitfalls:
Some learners try to decode idioms word by word and end up choosing literal but meaningless options. Others may link the word red with blood and assume it always relates to physical harm. The safe strategy is to memorise common idioms with their intended meanings, and whenever possible, recall example sentences. This helps to avoid confusing idioms with ordinary descriptive phrases.

Final Answer:
The idiom caught red-handed means Discovered in the act of doing wrong.