What is the typical figure used for illustrating a trend?

A line graph is the ideal choice for illustrating a trend because it effectively displays data points over time. This format allows viewers to easily identify and analyze the direction and rate of change in the data. With its continuous nature, a line graph connects individual data points with a line, visually representing the progression or regression of the trend.

In contrast, a block diagram primarily illustrates relationships or processes rather than temporal trends. A pie chart is best suited for showing proportions within a whole and lacks the ability to depict trends over time. While a bar graph can also illustrate trends, especially when comparing categorical data, it is generally not as effective as a line graph for showing changes over a continuous period. Therefore, the line graph stands out as the most suitable option for trend illustration.