When should a line graph be used? A. When the independent variable is continuous and shows a causal link to the dependent variable.
B. When the independent variable is composed of categories and does not show a relationship.
C. When there is no independent variable.
D. When the independent variable is continuous and does not show a relationship to the dependent variable.

A. When the independent variable is continuous and shows a causal link to the dependent variable.

Explanation:

A graph can be defined as the graphical representation of data (informations) on horizontal and vertical lines i.e x-axis and y-axis respectively.

In an experiment , the variable being manipulated by an experimenter is known as an independent variable while the dependent variable is the event expected to change when the independent variable is manipulated

Generally, a line graph should be used when the independent variable is continuous and shows a causal link to the dependent variable.

This ultimately implies that, a line graph should be used when the data changes continuously over time and as such there exist a linear relationship between the data (variables).

c. newton's third law of motion