Which graph represents the polar curve r is equal to 4 sine theta ?

Convert the polar equation using x = r cos θ, y = r sin θ, and r² = x² + y². From r = 4 sin θ, multiply by r to get r² = 4r sin θ, so x² + y² = 4y, or x² + (y − 2)² = 4. This is a circle centered at (0, 2) with radius 2, passing through the origin and the polar point (4, π/2), so the correct choice is D.

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