4? I'm not sure, since I'm in a rush.
Work:
1. Band 1, 2, 3
2. Band 2, 3, 4
3. Band 3, 4, 1
4. Band 1, 2, 4
The answer is D. You can rule out A and B by looking at the x value of 0 because the corresponding y value is 7 so you need to add 7 to a number multiplied by 0. And then you know it's not C because if you plug in the 0 for x it doesn't work.
False because multiple inputs can’t have the same output