Can someone help me with the question please

Answer:
Purple line: 4
Red dashed line: 2
Blue line: 1/2
Step-by-step explanation:
The purple line is the steepest line, therefore it has the biggest constant of proportionality or slope. Since 4 is the biggest number among the others, we attribute it to the purple line (the one with the point C on it).
Think of it this way:
[tex]y = ax+b \\[/tex]
here [tex]b = 0[/tex] so [tex]y = ax[/tex]
The greater a is, the greater y is. So for any value of x, y will be become bigger and bigger if we increase the value of a.
Take for example this one:
[tex]y = 2x \\[/tex]
Take [tex]x=2\\[/tex] therefore [tex]y =4[/tex]
Now take [tex]y = 4x[/tex] and take [tex]x =2[/tex] therefore [tex]y = 8[/tex]
When we increased this constant of proportionality, as you can see from 2 to 4, the value of y increase from 4 to 8.
Hope this is helpful. Think of it really carefully, and I'm sure you'll grasp the concept.