Concept:The question tests your knowledge of antonyms, so you must first understand the exact meaning of the underlined word.
Explanation:The word "callow" is used to describe a young person who is inexperienced and immature.
Such a person has not yet gained enough life knowledge or practical skills.
The teacher says Agoshito is a callow youth, meaning Agoshito is still raw and unseasoned.
To find the opposite, think of a word that indicates maturity and practical knowledge.
"An experienced" youth is someone who has been through many situations and has learnt from them.
The other options do not directly oppose the idea of inexperience.
"An ignorant" youth relates to lack of knowledge, not necessarily lack of experience.
"An idle" youth relates to laziness, and "an organized" youth relates to orderliness.
Thus, the correct antonym for "callow" is "experienced".
Answer:B. an experienced