Compute the partial derivatives of fx, y) = fz(x, y) = (enter a, b, c, or d) a. (enter a, b, c, or d) b. C. d. fy(x, y) = 4x a. (x² - y²)3/2 4xy (x² - y²) ³/2 - 4y (x² - y²)³/2 8xy (x² - y²) ³/2 b. C. -4y² (x² - y²)³/2 - 4xy (x² - y²) ³/2 - 4y (x² − y²)³/2 8y² (x² - y²)³/2 d. 4x x² - y²