<h2>Answer:</h2>
B. 3
<h2>Step-by-step explanation:</h2>A tangent is a line that passes through exactly one point on a circle. For any point on a circle, the radius and tangent line through that point are always perpendicular to each other making a right angle. If two triangles touch each other externally, then there will be 3 lines making right angle with radius of the circles at the point of intersection of circle and tangents. These three tangent lines are shown below. They are the black, blue and green ones.