What is the optimal solution to the following NLP (Use K-T conditions and the multiplier for the constraint)? Maxz=x1x2s.t.x12+x221 Select one: a. x1=42,x2=42,=42 b. x1=22,x2=22,=22 c. x1=41,x2=41,=41 d x1=21,x2=21,=21