Which situation would be more likely to occur in the modern era than in earlier periods of human history

The correct answer is a student in japan practices English by talking with students in Ireland over the internet

Doing anything over the internet would only be capable in the modern era of human history because the Internet did not exist until the second half of the twentieth century. Whether it is teaching or just communicating, it would only be possible in newer times and with the development of the internet as it is, it's highly likely it would be an event from the 21st century.