Which of the following words is an antonym of "Gullible"?

• Gullible (adjective)
English Meaning: Easily deceived or tricked, and too willing to believe everything that other people say.
Bangla Meaning: সহজে প্রতারণাযোগ্য।

Synonyms: Credulous (সরল বিশ্বাসী; বিশ্বাসপ্রবণ), Impressionable (সহজপ্রবণ), Naïve (সাদাসিধা). Unwary (অসতর্ক), Credible (সহজে বিশ্বাস করা যায় এমন)।
Antonyms: Cynical (নৈরাশ্যবাদীর আচরণসম্পন্ন), Suspicious (সন্দেহজনক; সন্দেহভাজন), Taunting (বিদ্রুপাত্মক), Fishy (সন্দেহজনক), Mistrustful (সন্দিগ্ধ, আস্থাহীন)।

Example Sentence:
1. After all, there are so many gullible people who believe whatever they read from internet!
2. At that early age she had been gullible and in love.

Source: Website Lecture.