Final answer:
If Z8, Z10, and Z11, Only lines r and s must be parallel. So, the option A describes all the lines that must be parallel - only lines r and s.
Step-by-step explanation:
The given information establishes that lines Z8, Z10, and Z11 are all parallel to each other and aligned along the x-axis.
In a coordinate system, lines parallel to the x-axis maintain a consistent y-coordinate while varying in the x-coordinate.
Since all three lines share this parallelism along the x-axis, they exhibit identical slopes, indicating their equivalence in terms of direction.
Furthermore, parallel lines never intersect, reinforcing the notion that these lines share a common orientation along the x-axis without converging or diverging.
The statement "Only lines r and s must be parallel" contradicts the established parallelism of Z8, Z10, and Z11, as all three lines, including r and s, exhibit this characteristic parallelism along the x-axis.
Therefore, The option A is correct, not only lines r and s but also lines Z8, Z10, and Z11 are parallel to each other.