The following dialog is for questions 18 to 20.

Mr. Alfian: Hasn't Nindya arrived home, dear?

Mrs. Sarita: No, dear, she has an extra-curricular activity today.

Mr. Alfian: I think ninth grade students should be free from extra-curricular activities. They must focus on the final examinations.

Mrs. Sarita: I don't think so. They must have balanced skills.

Mr. Alfian: What do you mean?

Mrs. Sarita: l mean students should not only gain good knowledge but also good skills, for example scouting, dancing, singing and martial arts. These activities will improve their self-confidence and characters. They should not be under pressure, so they can face examinations well.

Mr. Alfian: That's good, but what if they are exhausted and then, reluctant to prepare themselves for the examinations?

Mrs. Sarita: It won't happen, dear. I'm absolutely sure that extra-curricular activities will improve their characters, including their responsibility to achieve the best results for a better future.

Mr. Alfian: You're right. Let's hope for the best.

Who are talking in the dialog?