Which of the following best describes the slope of the line below ?
a) undefined
b) positive
c) negative
d) zero

we have

The equation of the graphed function is

we know that

The slope of the line parallel to the x-axis is equal to zero and the slope of the line parallel to the y-axis is undefined

In this problem

The line is parallel to the x-axis

so

The slope is equal to zero

Remember that

The formula to calculate the slope is equal to

In this problem the value of y is constant

so

therefore

the answer is

Zero

in mathematics, a function is a relationship between two variables such that the value of one of the variables, called the dependent variable, is determined by the value of the other variable, called the independent variable. there is a specific term we use to describe the set of independent variables of a function.