Concept:The problem uses the property of inverse sine: sin−1(−x)=−sin−1(x) for x in [−1,1], and the known value sin−1(21)=6π.Explanation:Step 1: Simplify sin−1(−21). Sine inverse of a negative angle gives a negative angle. So sin−1(−21)=−sin−1(21)=−6π.Step 2: Substitute into the expression: sin[3π−(−6π)]=sin(3π+6π).Step 3: Add the angles: 3π+6π=62π+6π=63π=2π.Step 4: Evaluate sin(2π)=1.Answer:The value is 1, which corresponds to option D.