Coordinates of the vertices B and C of a ΔABC are (2, 0) and (8, 0) respectively. The vertex A is varying in such a way that 4tan(2B)⋅tan(2C)=1 . Then, the locus of A is
a. 25(x−5)2+16y2=1
b. 16(x−5)2+9y2=1
c. 25(x−5)2+9y2=1
d. 16(x−5)2+25y2=1