The correct answer is: Line graph
Also named line chart, this is used to visualize the value of something over time. It helps showing multiple series of closely related series of data. They are formed by a horizontal x-axis and a vertical y-axis. Most of times the x-axis is a timescale or a secuence of intervals and the y-axis has a quantitative value. The line graphs are drawn by plotting data points on a Cartesian coordinate grid, then connecting them with a line. Directions of the lines usually show what happens with the data in a simple way, an upward slope indicates an increase in values and a downward slope the decrease fo values. In this way the line's journey accross the graph can create a different pattern reveling trends.