Question 18A circle of radius $2$ has center at $(2,0).$ A circle of radius $1$ has center at $(5,0).$ A line is tangent to the two circles at points in the first quadrant. Which of the following is closest to the $y$-intercept of the line?$\frac{\sqrt2}{4}$$\frac{\sqrt8}{3}$$1+\sqrt3$$2\sqrt2$$3$