Fill in the blank with the most appropriate word: Haider wanted to convince his parents, but his attempts were _.

Explanation

Correct Answer: b. In vain - Explanation: The correct answer is 'in vain,' which means that the attempts were unsuccessful. - Why other options are not correct: - a. Successful: Successful attempts do not convey the sense of failure described in the sentence. - c. Plausible: Plausible attempts do not fit the context of being unsuccessful. - d. Coercive: Coercive attempts imply force, which is not the intended meaning.