Concept:The test requires identifying the word that is most nearly opposite in meaning to the underlined word, "refined," so that it correctly fills the gap.
Explanation:The word "refined" describes someone who is elegant, polished, and cultured in manners or taste.
The word "crude" describes someone who is rough, raw, or lacking refinement and good manners.
Thus, "crude" is the direct opposite of "refined."
The sentence uses "but" to show contrast between Tom and his brother, so the missing word must be an antonym of "refined."
Now, check the other options: "arrogant" means having an exaggerated sense of self-importance; "unskillful" means lacking skill; and "foolish" means lacking good sense.
None of these is a direct opposite of "refined."
Therefore, "crude" is the correct choice.
Answer:B. crude