Step 1: Understanding the original sentence.
The original sentence expresses that defining difficult or uncommon words may cause discomfort. Therefore, the rewritten sentence must preserve this meaning without changing tone or meaning.
Step 2: Evaluating the options.
(A) Suggests no one should be asked. This adds a judgment not present in the original sentence.
(B) Says one should be asked even if uncomfortable, which contradicts the original meaning.
(C) Is incomplete and direct; it does not reflect the conditional situation expressed originally.
(D) Correct — It expresses the same meaning: defining difficult words may cause difficulty or discomfort.
Step 3: Conclusion.
Option (D) is grammatically correct and semantically closest to the original meaning.