Answer: A horizontal line.
- A A line through origin
- B A vertical line
- C A horizontal line
- D A diagonal line
Correct answer: C. A horizontal line
Explanation: y = constant represents a horizontal line parallel to the x-axis.
The slope of a line is the ratio of vertical change (rise) to horizontal change (run) between any two points on it - equivalently, the tangent of the angle θ the line makes with the positive x-axis.