What type of graph uses lines to present data that can be stable or show trends in inclination or declination?

A line graph is the correct choice because it is specifically designed to display data points over time and is particularly effective in illustrating trends, whether they are increasing or decreasing. The connecting lines between the data points help to visualize the changes in values, making it easy to see patterns or fluctuations in the data over a continuous range, such as time intervals.

Line graphs are ideal for showing stable values as well, since they allow for quick visual assessment of where data remains constant or fluctuates over periods. This capacity to depict both trends in inclination (when values rise) and declination (when values fall) makes line graphs a preferred option for many types of data analysis, especially in fields like economics, environmental studies, and health statistics.

Bar graphs, on the other hand, are typically used for comparing quantities between different categories but do not effectively illustrate trends over time. Pie charts are useful for displaying parts of a whole at a particular time but lack the ability to show changes over time. Scatter plots help in showing relationships between two variables but do not inherently demonstrate trends in the same continuous manner as line graphs do.