VOCABULARY — Choose the best synonym (same meaning) of the highlighted word, based on the sentence. Sentence: “The young man appears to be quite HEADSTRONG.”

Introduction / Context:
“Headstrong” describes a person who is willful, self-willed, and refuses to be guided or restrained—often synonymous with stubborn. The question asks you to choose the closest synonym that preserves this sense of stubborn will.

Given Data / Assumptions:

• The description is about personality, not physical strength or intelligence.
• Context implies refusal to yield or listen.
• We must avoid pejoratives that shift meaning (e.g., stupidity) or unrelated traits (e.g., humor).

Concept / Approach:
“Obstinate” means stubbornly adhering to an opinion, purpose, or course despite reason or persuasion—precisely parallel to “headstrong.” “Thick-headed” implies slow-witted, which is about intelligence, not willfulness. “Robust” is about strength or health. “Witty” concerns humor and quickness of mind.

Step-by-Step Solution:
1) Map key trait: headstrong = stubborn, willful.2) Compare: “obstinate” matches; others are off-axis.3) Substitution test: “appears to be quite obstinate” keeps intent intact.4) Confirm register: both are common descriptors in behavioral contexts.

Verification / Alternative check:
Thesauri list headstrong with synonyms like obstinate, willful, stubborn—showing strong overlap.

Why Other Options Are Wrong:
A) “thick-headed” — intelligence insult, not willfulness.C) “robust” — physical/figurative strength, not attitude.D) “witty” — humor skill, unrelated.

Common Pitfalls:
Confusing stubbornness with lack of intelligence. A person can be clever and still be headstrong.

Final Answer:
obstinate