Computer networks make setting appointments easier by

telephoning attendees
sending out invitations
reassigning tasks to enable attendance
sending electronic reminders
providing a common calendar

The correct answer is: "Computer networks make setting appointments easier by sending electronic reminders".

Explanation:

This is a feature almost all computer networks have, and if not there are still applications and plugins for that. These networks schedule, organize and set appointments and others according to the calendar, weeks, days, time, and working plan. Their reminders depend on the ones previously chosen, such as by email notifications, system's alarm, networks' events, mobiles' agenda, among others.