Let the ellipse $3x^2 + py^2 = 4$ pass through the centre $C$ of the circle $x^2 + y^2 - 2x - 4y - 11 = 0$ of radius $r$. Let $f_1, f_2$ be the focal distances of the point $C$ on the ellipse. Then $6 f_1 f_2 - r$ is equal to:
\( 68 \)
\( 74 \)
\( 78 \)
\( 70 \)