In the following idiom question, choose the option that best expresses the meaning of the phrase:\n\n"Make an ass out of" someone.

Introduction / Context:
This question is based on the informal idiom make an ass out of someone or oneself. The phrase uses ass in its older sense of donkey and metaphorically refers to someone looking foolish. It is often used to describe a situation in which a person acts in such a way that others see them as silly or ridiculous. The question asks you to select the option that best captures this meaning.

Given Data / Assumptions:

• Idiom: make an ass out of.
• Options: cause someone or oneself to look foolish or stupid, work very hard like a donkey, be smart but act dumb, make a mistake.
• We assume the phrase is used in everyday informal English conversation.

Concept / Approach:
Make an ass out of someone means to make that person seem silly, ridiculous, or foolish in front of others. When used reflexively, such as make an ass out of myself, it means the speaker recognises that their behaviour made them appear stupid. While making a mistake may be part of the situation, the core idea is public embarrassment or foolish appearance, which is best captured by the first option.

Step-by-Step Solution:
Step 1: Recall typical usage: He made an ass out of himself at the party. Step 2: Note that this does not mainly mean he worked hard or simply made a minor error, but that he looked ridiculous in front of others. Step 3: Compare this meaning with each option. Step 4: Choose cause someone or oneself to look foolish or stupid as the closest match.

Verification / Alternative check:
Imagine someone telling a story: I tried to impress everyone with my speech, but I made an ass out of myself. This clearly means the person ended up looking foolish, not that they worked hard. Replacing the phrase with the full definition gives I caused myself to look foolish or stupid, which preserves the meaning. None of the other options can be substituted without changing the sense of embarrassment.

Why Other Options Are Wrong:
Option B, Work very hard like a donkey, is a different expression, sometimes covered by phrases like work like a donkey, but that is not the meaning here. Option C, Be smart but act dumb, partially overlaps with pretending to be less intelligent, but make an ass out of does not necessarily involve pretending; it is about ending up looking foolish. Option D, Make a mistake, is too general and does not imply public embarrassment or ridicule, which are central to the idiom.

Common Pitfalls:
Students sometimes focus on the word ass and associate it only with hard labour or with any insult. It is important to consider the entire phrase and the way it appears in real sentences. Idioms often carry specific emotional tones, such as shame or ridicule, that must be preserved when selecting the meaning.

Final Answer:
The idiom make an ass out of means to cause someone or oneself to look foolish or stupid.