question_answer

For \[a{{x}^{2}}+2hxy+3{{y}^{2}}+4x+8y-6=0\] to represent a circle, one must have

A)            \[a=3,\ h=0\]                           

B)            \[a=1,\ h=0\]

C)            \[a=h=3\]                                

D)            \[a=h=0\]