Concept:The sentence has a word usage error. The word "defers" means to postpone or yield, but the intended meaning is "is different from".
Explanation:The error is in part (b) of the sentence.
The word "defers" is incorrect here.
The correct word should be "differs".
"Differs" means to be unlike or distinct.
The sentence talks about the written statement being different from the oral statement.
Therefore, "defers" must be replaced with "differs".
The corrected sentence is: "His written statement differs in several important respects from his oral statement."
Answer:The error is in part (b). So the correct choice is (b).