Analyze the sentence: "The student studied hardly for the exam but still failed to pass.''
Step 1: Identify error
- The adverb "hardly'' means barely or scarcely, which is not correct here.
- The correct word is "hard,'' meaning with effort.
- So, it should be "The student studied hard for the exam.''
Step 2: Correct sentence
"The student studied hard for the exam but still failed to pass.''
Conclusion
Error is in part (B).