For the cases below, select which type of communication $($i$.$e$.,$ Interpersonal, Non$-$Verbal, Written, or Oral$)$ is best suited for the occasion and justify your response.

$1.$ There is a new batch of salespeople joining your team, and you need to provide them with an example of how to communicate with a prospective customer.

$2.$ A salesperson wanted to chat with you about a sensitive matter $($e$.$g$.,$ a death in the family$)$ and requires some time off.

$3.$ You must dismiss an employee that has very poor performance and has not improved.

$4.$ You must update the sales pitch for the telemarketing team.