If you wanted to make the graph of y=3x+1 steeper which equation could you use

When you want to make the graph of a line steeper, the slope of the line has to be made greater. The slope of your line y = 3x+1 has a slope of 3. A from above has the same slope, so it's not A. B has a negative slope, so it's not B. C has a much less steep slope at 1/2, so that leaves D. D is your answer and if you graph it you will see how much steeper that line is when compared to your original graph of y = 3x + 1.