The Solution to the Differential Equation of a Damped Oscillator $\omega$

The solution to the differential equation of a damped oscillator, for the case in which the damping is small, is
X = A₀e^{-(b/2m) t} cos( $\omega$ 't + $\delta$ )
The phase constant $\delta$ is determined by the

A) spring constant k and the mass m of the system.
B) spring constant k and the damping coefficient b of the system.
C) initial velocity of the system.
D) initial displacement of the system.
E) c and d