y = -0.4x
1) It is a straight line
2) I passes through the origin (0,0), because the y-intercpet is 0.
3) The slope is negative, so it passes throuh II and III quadrants
4) The magnitude of the slope = 0.4
4) The angle of the line with the negative side of the x-axis is that whose tan is 0.4 => angle = 21.8 °
With all that information you can identify the graph, given that you didn't include the options.