Two circles of radii 18 cm and 12 cm intersect each other and the length of their common chord is 16 cm. What is the distance (in cm) between their centres?

$2\sqrt{5}(2+\sqrt{13})$ $2\sqrt{5}(4-\sqrt{13})$ $2\sqrt{5}(4+\sqrt{13})$ $2\sqrt{5}(-2+\sqrt{13})$

$2\sqrt{5}(2+\sqrt{13})$