b

$ R = 5\Omega$

$\text{Capacitive Reactance} X_C = \frac{1}{\omega C} = \frac{1}{ 320\times 10^{-3}} = 3\Omega$ 

$\text{Inductive Reactance} X_L = \omega L = 320\times 0.025 = 8\Omega$ 

$\text{Total Reactance } X = X_L - X_C = 5\Omega $

$\text{Total Impedance } Z = \sqrt {R^2+(X_L - X_C)^2} = 5\sqrt 2 \Omega = 7\Omega$

$\text{Phase Difference } = tan^{-1}\frac{X}{R} = 45^o$