Which type of graph is used to represent trends of several items simultaneously?

A multiple line graph is effective for representing trends of several items simultaneously because it allows for the visualization of data series over time or across categories on the same set of axes. Each line in the graph represents a different item or category, making it easy to compare their trends at a glance. For instance, if you are tracking the performance of various sales items over several months, a multiple line graph can clearly show how each item is trending, allowing for easy comparisons between their trajectories.

In contrast, bar graphs and column charts are typically used for comparing quantities for different categories but may not effectively show trends over time. While they can show changes in data across categories, they do not allow for the same level of clarity when tracking multiple trends over a continuous variable. Pie charts are useful for showing parts of a whole at a single point in time, but they do not represent trends or changes, making them unsuitable for this specific purpose. Thus, the multiple line graph stands out as the best choice for visualizing and analyzing trends across multiple items simultaneously.