D. 3 if you get this right i will mark you as a brainliest

One, and more specifically, the tangent line touching the right-most point on each circle (red). Any other tangent lines of the larger circle (green) won't be tangent to the smaller circle since they don't touch it at any point, and any other tangent lines of the smaller circle (blue) won't be tangent to the larger one, since they intersect the large one at two points.

because they could drop even lower..