question_answer

Equation \[a{{x}^{2}}+b{{y}^{2}}+c{{z}^{2}}+2fyz+2gxz+2hxy\] \[+2ux+2vy+2wz+d=0\]represents a sphere, if                                 [MP PET 1990]

A)            \[a=b=c\]                                  

B)            \[f=g=h=0\]

C)            \[v=u=w\]                                 

D)            \[a=b=c\] and \[f=g=h=0\]