If a variable tangent to the circles x²+y²=1 intersects the ellipse x²+2y²=4 at points P and Q then the locus of the point of intersection of tangents to the ellipse at P and Q is

A. foci are (±2√5,0)
B. eccentricity √3/4
C. eccentricity is √5/2
D. latus-rectum is of length 2 units