Simplify the expression: 4x^(3/2) - 20x^(1/2) + 16x^(-1/2). Which of the following options is the correct simplified form? A) 4x^3 - 20x + 16x^(-1), B) 4x^(3/2) - 20x^(1/2) + 16x^(-1/2), C) 4x^(3/2) - 20x^(1/2) + 16/x^(1/2), D) 4x^3/2 - 20x^(1/2) + 16/x^(1/2).