Answer:
The y-intercept must be zero.
It is possible that the line is horizontal.
Explanation:
The description states that the line "crosses both axes at the origin." That would mean that the point (0,0) is on the graph. The y-intercept is the value of y when x=0. We see that it is zero in this case (0,0).
The description says nothing about the slope. So it could be either positive or negative. But it could also mean that the slope is zero. A zero slope would be a horizontal line. So that is a second statement that is true: "It is possible that the line on the graph is horizontal."