Isaac and Sakura are both doing a science experiment where they are measuring the temperature of a liquid over time. Graphs that represent each of their data are shown below. A graph titled Isaac's Experiment has time (minutes) on the x-axis and Temperature (degrees Fahrenheit) on the y-axis. A line goes through points (0, 80) and (2, 70).

A graph titled Sakura's Experiment has time (minutes) on the x-axis and Temperature (degrees Fahrenheit) on the y-axis. A line goes through points (0, negative 80) and (8, 0).

Which statement is correct?
The slope of the graph that represents Isaac’s data is positive, and the slope of the graph that represents Sakura’s data is positive.
The slope of the graph that represents Isaac’s data is positive, and the slope of the graph that represents Sakura’s data is negative.
The slope of the graph that represents Isaac’s data is negative, and the slope of the graph that represents Sakura’s data is positive.
The slope of the graph that represents Isaac’s data is negative, and the slope of the graph that represents Sakura’s data is negative. In your own words, describe how matter is identified.