In the following question, choose the option that best expresses the meaning of the given word NEFARIOUS by selecting the most appropriate synonym from the four alternatives.

Introduction / Context:
This vocabulary question tests the meaning of the word nefarious, which is a common high level English term used in newspapers, novels, and competitive examinations. The task is to choose a synonym, that is, a word with the closest meaning, from the four given options. A strong vocabulary is very important for scoring well in English sections of exams such as SSC, banking, and other government tests.

Given Data / Assumptions:
The word given in the question is nefarious. The answer choices are EXCITED, WICKED, RIGOROUS, and BENIGN. Only one of these options has nearly the same meaning as nefarious. We assume standard modern English usage as found in good dictionaries and formal writing. No special technical or regional meaning is suggested by the question.

Concept / Approach:
Nefarious is an adjective used to describe actions, activities, or people that are extremely bad, immoral, or evil. It is often seen in phrases like nefarious activities, nefarious schemes, or nefarious criminals. Therefore, we need to look for an option that conveys moral evil or great wickedness. Wicked is an adjective that means morally wrong, evil, or sinful, and it fits very closely. The other options describe emotional excitement, strictness, or kindness, so they do not match the moral sense of nefarious.

Step-by-Step Solution:
Step 1: Recall or infer the meaning of nefarious. It describes something extremely immoral or evil. Step 2: Examine each option and connect it with its core meaning in everyday English. Step 3: Note that EXCITED relates to strong emotion, RIGOROUS relates to strict or thorough action, and BENIGN means gentle or kind. Step 4: Observe that WICKED refers to very bad or evil behaviour, often in a moral sense. Step 5: Match nefarious with WICKED as the closest synonym because both describe evil and morally wrong actions.

Verification / Alternative check:
To verify, imagine a sentence like The gang was involved in nefarious activities. Replacing nefarious with each option, only The gang was involved in wicked activities makes full sense. The sentences with excited activities, rigorous activities, or benign activities sound odd and unnatural in this criminal context. Another quick check is to look at common collocations: nefarious plot and wicked plot both sound natural, whereas excited plot or benign plot do not. This confirms that wicked is the best synonym here.

Why Other Options Are Wrong:
EXCITED describes a person who is very enthusiastic or emotionally aroused, not evil or immoral, so it fails to capture the sense of nefarious.
RIGOROUS means strict, thorough, or very exact, which may be demanding but is not necessarily bad or immoral.
BENIGN usually means gentle, kind, or harmless, and it is almost the opposite of evil, which makes it completely unsuitable as a synonym for nefarious.

Common Pitfalls:
Students sometimes confuse nefarious with words like notorious or nervous because they may have seen them in similar contexts. Another common problem is to choose an option that simply looks difficult or formal. In vocabulary questions, the safest approach is to focus on the precise meaning and typical usage. Learning a few example sentences for tricky words like nefarious will help fix them in long term memory and avoid confusion during the exam.

Final Answer:
The word that best expresses the meaning of NEFARIOUS is WICKED.