Vocabulary – Choose the option that BEST expresses the meaning of the underlined word in context. Sentence: Only those who are gullible take every advertisement seriously.

Introduction / Context:
“Gullible” describes a person who can be easily persuaded or deceived because they are overly trusting. In advertising contexts, gullible consumers accept claims without verification. Recognizing near-synonyms helps choose precise meanings in reading passages.

Given Data / Assumptions:

• Target word: gullible.
• Context: believing every advertisement.
• Options include words about mistakes, emotions, trust, and realism.

Concept / Approach:
The core feature of “gullible” is unwary trustfulness. A close synonym emphasizes not suspecting trickery or false claims. Among the options, “unsuspecting” best matches this trait.

Step-by-Step Solution:
Define the pivot: gullible = easily deceived because too trusting.Scan choices: “unsuspecting” = not expecting deception; “fallible” = liable to error; “enthusiastic” = eager; “unrealistic” = not practical.Map to context: taking ads at face value aligns with “unsuspecting”.Select the synonym that fits both meaning and context.

Verification / Alternative check:
Substitute: “Only those who are unsuspecting take every advertisement seriously.” This retains the original logic.

Why Other Options Are Wrong:

• fallible: everyone is fallible; it does not imply credulity.
• enthusiastic: refers to eagerness, not naivety.
• unrealistic: relates to practicality, not trustfulness.

Common Pitfalls:
Confusing “gullible” with “foolish” or “stupid.” Gullibility is about trust, not intelligence.

Final Answer:
unsuspecting