Question

Please give an explanation with your answer.
Which of the following is NOT a valid completion of the statement below?

"Finding a tangent line to a function at a point is basic to calculus because___"
A. It uses the limit process
B. It is equivalent to finding the slope of the secant line at that point.
C. It is equivalent to finding the slop of the curve at that point.
D. The slope of the tangent line is equal to the slope of the curve.