Final answer:
A timeline shows the order of events in a specified time period, organized chronologically. It typically displays events from left to right, to convey the sequence from earliest to latest.
Step-by-step explanation:
The correct answer to the student's question is: (a) Timeline; chronologically. A timeline is a graphical representation of a sequence of events, displayed chronologically, which means they are shown in the order that they occurred in time. Timelines are divided left-to-right to represent the progression from earlier to later events. They are helpful for understanding the historical context and sequence of events, such as studying the timelines of ancient civilizations like the Americas, Africa, and the rise of various empires. By contrast, other graphical tools such as graphs and charts serve different purposes in visually organizing data, using various axes to represent different variables or categories.