Final answer:
A company should use a line graph to chart employee absences over a two-year period, as it shows trends and changes over time efficiently.
Step-by-step explanation:
To effectively chart employee absences over a two-year period, the appropriate type of graph would be a line graph. This is because a line graph is well-suited for showing changes over time. Each point on the graph would represent the number of absences at a particular time interval (such as monthly or quarterly), and the line connects these points to show trends. While a bar chart could also be used to represent the data clearly by comparing the number of absences for different periods, the line graph provides a more continuous view of the data, making it easier to identify patterns or fluctuations in employee absences over the period. A scatter plot is more commonly used for numerical data where you want to show a correlation between two variables, and a pie chart would not be appropriate here as it is better suited for showing how a whole is divided into proportional parts at one specific point in time, rather than how data changes over time.