In English vocabulary, select the antonym (word opposite in meaning) of the verb adulterate, which means to make something impure by adding inferior or harmful substances.

Introduction / Context:
This question tests your understanding of antonyms and vocabulary related to quality and purity. The verb adulterate is often used in news articles about food safety, medicines, fuel and other products where harmful or inferior substances may be mixed in. Knowing its opposite helps you understand discussions about pure and contaminated goods. In many competitive exams, such vocabulary questions appear in the English section as quick checks of your lexical knowledge.

Given Data / Assumptions:

• Target word: adulterate.
• Options: attenuated, purify, vitiated, dilute.
• Adulterate means to make something impure or poorer in quality by adding inferior or harmful substances.
• We must select the option that expresses the opposite action.

Concept / Approach:
The clear opposite of making something impure is making it pure or cleaning it of contaminants. The verb purify directly means to make pure, remove impurities or cleanse. Attenuated usually means weakened or decreased in force. Vitiated means spoiled, impaired or corrupted, which is quite close to adulterated rather than opposite. Dilute means to make a liquid weaker or thinner, often by adding more solvent or water, and is similar in effect to adulterate in many practical contexts. Therefore, purify is the only true antonym here.

Step-by-Step Solution:
Step 1: Recall the meaning of adulterate: to make impure or of lower quality by adding inferior or harmful substances. Step 2: Examine purify. It means to make pure or free from contaminants, which is directly opposite to adulterate. Step 3: Examine attenuated. It means reduced in strength or force and does not necessarily imply purity. Step 4: Examine vitiated. It means spoiled, impaired or corrupted, which is very similar to adulterated, not the opposite. Step 5: Examine dilute. It means to thin or weaken by adding liquid, often leading to lower concentration and sometimes poorer quality, again similar in effect to adulterate.

Verification / Alternative check:
Think of common phrases. We talk about adulterated milk, meaning milk mixed with water or harmful substances. The action needed to correct that would be to purify the milk, removing contaminants. Attenuated milk would simply be weaker, and diluted milk would be thinner but still mixed with something else. Vitiated product refers to something damaged or corrupted, just like adulterated. Only purify clearly restores or achieves purity. This linguistic and logical check confirms that purify is the correct antonym.

Why Other Options Are Wrong:

• attenuated: Refers to reduced strength or intensity, not to the quality of being pure or impure, so it is not a direct opposite.
• vitiated: Means impaired, spoiled or corrupted, which is close in meaning to adulterated rather than the reverse.
• dilute: Often involves adding more liquid to make something thinner or weaker, a process that in many cases can be a form of adulteration rather than purification.

Common Pitfalls:
Students may confuse attenuated and dilute with antonyms because they focus only on changes in concentration or strength without considering purity. Another pitfall is to choose vitiated because it appears complex and advanced, but that is exactly why exam setters include it as a trap; it is a synonym, not an antonym. To succeed in such questions, always start by clearly articulating the meaning of the base word, then match that meaning or its opposite with the options carefully instead of guessing based on word complexity.

Final Answer:
The correct antonym of adulterate is purify, as purifying reverses or avoids the contamination that adulteration causes.