The correct answer is C) line of best fit, used to represent the linear trend in the data.
When data is displayed with a scatter plot, it is often useful to attempt to represent that data with the equation of a straight line. This line is called a line of best fit, and what is its purpose is to determine if a line represents a linear equation.
In statistics, the term "line of best fit" defines a straight line that represents the data that is on the scatter plot. It determines the relationship that two variables have. Many times it is used in regression analysis when you want to express statistical information in research fields such as finances, biology, or science.