I picked the yellow one, was I correct?

Yes you are correct.

You can’t get a negative output since these brackets -> | | indicate absolute values

Absolute values means the answer you get inside the brackets should be positive at the end

For ex:

| -8 + 2 |
| -6 |
= 6 (the absolute brackets make this a positive)

Note: if the answer inside the bracket is already a positive it will remain a positive.