Final answer:
To find the slope of a parallel line, you need to know the slope of the original line. The slope of a parallel line is the negative reciprocal of the original line's slope.
Step-by-step explanation:
The correct answer is B) It is the negative reciprocal of the original line's slope.
To find the slope of a parallel line, you need to know the slope of the original line. For a line with slope m, the slope of any parallel line will be the negative reciprocal of m.
For example, if the original line has a slope of 3, then the slope of any parallel line will be -1/3.