Locate and Classify All Critical Points for the Given Function $f(x, y)=1-\left(x^{2}-y^{2}\right)$

Multiple Choice

Locate and classify all critical points for the given function.
- $f(x, y) =1-\left(x^{2}-y^{2}\right)$

A) Minimum of 1 at $(0,0)$
B) Saddle point at $(0,0)$
C) Maximum of 1 at $(0,0)$
D) None of the above is correct.