Answer
The reaction $(a)$ involves strong bases and strong nucleophiles.
Work Step by Step
In reaction $(a)$, $Ba(OH)_2$ is a strong base. So, the reaction $(a)$ involves strong bases and strong nucleophiles.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.