The Least Costly Way to Produce Any Given Level of Output

The least costly way to produce any given level of output is indicated by

A) the point of intersection between the isoquant corresponding to that level of output and the Y-axis.
B) the point of intersection between the isoquant corresponding to that level of output and the X-axis.
C) the point of tangency between an isocost line and the isoquant corresponding to that level of output.
D) the isocost line corresponding to that level of output.