Which line is a linear model for the data?

Scatter plot on a first quadrant coordinate grid. The horizontal axis is labeled Variable M. The vertical axis is labeled Variable N. Points are plotted at (zero, one hundred), (five, one hundred ten), (ten, eighty), (fifteen, fifty), (twenty, seventy), (twenty, one hundred), (twenty-five, sixty), (thirty, twenty), (thirty, seventy-five), (thirty-five, sixty-five), (forty, forty), (forty-five, ten). A line is drawn through (twenty, seventy), and (twenty-five, sixty).

Scatter plot on a first quadrant coordinate grid. The horizontal axis is labeled Variable M. The vertical axis is labeled Variable N. Points are plotted at (zero, one hundred), (five, one hundred ten), (ten, eighty), (fifteen, fifty), (twenty, seventy), (twenty, one hundred), (twenty-five, sixty), (thirty, twenty), (thirty, seventy-five), (thirty-five, sixty-five), (forty, forty), (forty-five, ten). A line is drawn through (fifteen, fifty) and (twenty, one hundred).

Scatter plot on a first quadrant coordinate grid. The horizontal axis is labeled Variable M. The vertical axis is labeled Variable N. Points are plotted at (zero, one hundred), (five, one hundred ten), (ten, eighty), (fifteen, fifty), (twenty, seventy), (twenty, one hundred), (twenty-five, sixty), (thirty, twenty), (thirty, seventy-five), (thirty-five, sixty-five), (forty, forty), (forty-five, ten). A line is drawn through (fifteen, fifty) and (thirty, twenty).

Scatter plot on a first quadrant coordinate grid. The horizontal axis is labeled Variable M. The vertical axis is labeled Variable N. Points are plotted at (zero, one hundred), (five, one hundred ten), (ten, eighty), (fifteen, fifty), (twenty, seventy), (twenty, one hundred), (twenty-five, sixty), (thirty, twenty), (thirty, seventy-five), (thirty-five, sixty-five), (forty, forty), (forty-five, ten). A line is drawn through (thirty, twenty) and (thirty-five, sixty-five).