Final answer:
Manman and Serafina had to convince Pierre to go to the doctor by effectively communicating and showing care and concern.
Step-by-step explanation:
Manman and Serafina had to convince Pierre to go to the doctor. They may have used different methods such as explaining the importance of seeking medical help, offering support and reassurance, or even using persuasion techniques to make him understand the consequences of not going to the doctor. By effectively communicating and showing care and concern, Manman and Serafina were able to convince Pierre to go to the doctor.