If the First Partial Derivative of a Lagrangian Function of Two

Multiple Choice

If the first partial derivative of a Lagrangian function of two decision variables are equal to zero at a point, then the point is

A) a saddle point maximum if the mixed partial is negative
B) a local maximum if the second partials are negative and $\mathrm{D}>0$
C) a global maximum if the second and mixed partials are all positive
D) a global minimum if the second partials are positive and $\mathrm{D}<0$