$$6 | \mathrm { AB } | = 3 | \mathrm { BC } | = 2 | \mathrm { CD } |$$
Above, three semicircles with diameters $[ \mathrm { AB } ] , [ \mathrm { BC } ]$ and $[ \mathrm { CD } ]$ with collinear centers are drawn inside a semicircle with diameter [AD], and the region between them is painted as shown in the figure.
If the perimeter of the painted region is $\mathbf { 24 \pi }$ units, what is its area in square units?
A) $44 \pi$
B) $48 \pi$
C) $52 \pi$
D) $56 \pi$
E) $60 \pi$