In the following question, out of the four alternatives, select the option that best expresses the meaning of the given idiom or phrase. Keep under one's hat

Introduction / Context:
This idiom question asks for the meaning of the phrase "keep under one's hat". In English, this expression is used when you want someone to keep information confidential and not tell others. It does not refer literally to hiding money or objects under a hat, but figuratively to hiding an idea or plan in your mind, unseen by others.

Given Data / Assumptions:

• Idiom: "Keep under one's hat".
• Options: Keep all your wealth in your home; To keep something a secret; Steal and hide something; Take care of somebody else's valuables given to you for safe keeping.
• We assume the idiom is being used in its common figurative sense about information, not physical objects.

Concept / Approach:
To "keep something under your hat" means to keep it to yourself, not to reveal it publicly. The hat symbolically covers your head, where your thoughts are, so the image suggests that the information remains hidden in your mind. The correct answer must therefore refer to secrecy about information, not to physical storage or theft. Among the given options, "To keep something a secret" exactly captures this idea.

Step-by-Step Solution:
Step 1: Recall common usage of the idiom, such as "I'll tell you my plan, but keep it under your hat."Step 2: Understand that in such sentences, the speaker is asking the listener not to tell anyone else.Step 3: Examine option B, "To keep something a secret". This is a direct restatement of the idiom's meaning.Step 4: Examine option A, "Keep all your wealth in your home". This changes the topic from information to money and is unrelated to the idiom.Step 5: Examine options C and D, which involve stealing or storing valuables. These again focus on physical objects, not on hidden information, and therefore do not express the idiom's true sense.

Verification / Alternative check:
Consider example dialogues: "I might be getting a promotion, but keep it under your hat for now" clearly means "don't tell anyone." If you replaced the phrase with "keep all your wealth in your home" or "steal and hide something", the sentence would become absurd. The idiom always appears in contexts where some news, plan, or secret is shared with instructions not to spread it further. This reinforces that secrecy, not physical hiding of items, is the key meaning.

Why Other Options Are Wrong:
Option A, "Keep all your wealth in your home", suggests a financial decision or security measure, which has nothing to do with idiomatic "under your hat". Option C, "Steal and hide something", introduces the idea of theft, which is not implied by the idiom. Option D, "Take care of somebody else's valuables given to you for safe keeping", could be described by phrases like "look after" or "hold in trust", but it does not match the mental, informational secrecy that "keep under one's hat" refers to.

Common Pitfalls:
Because the phrase mentions a hat, some learners think it must be about physically hiding objects under a hat or otherwise concealing material things. Another pitfall is to confuse it with expressions about storing wealth or valuables. To avoid these errors, remember that many idioms are metaphorical: here, the hat represents the head, and keeping something under it means keeping it in your mind only, without letting it out into the open.

Final Answer:
The idiom "keep under one's hat" means to keep something a secret.