Final answer:
C)the slope of the line. The constant of variation in direct variation has the same value as the slope of the line.
Step-by-step explanation:
The constant of variation in direct variation has the same value as the slope of the line.
In direct variation, the equation of the line is in the form of y = kx, where k represents the constant of variation. The slope of the line, represented by the coefficient of x, is also equal to k. So, the correct answer is C) the slope of the line.