How does a line with a slope of 0 visually differ from a line with a slope of 1 on a graph?

• A. The line with a slope of 0 is vertical, while the line with a slope of 1 is horizontal.
• B. Both lines are horizontal.
• C. Both lines slope upward from left to right.
• D. The line with a slope of 0 is horizontal, while the line with a slope of 1 slopes upward.

Answer: (D)