18. Find the area of the region that lies inside both the curves r = 4sinθ and r = 4 cosθ .
(A) 2π + 1
(B) 2π −1
(C) 2π + 4
(D) 2π − 4
(E) 2π

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統計： A(0), B(0), C(1), D(1), E(0) #2264882