The rotation of the arm OA about O is defined by θ = 0.15t², where θ is expressed in radians and t in seconds. Collar B slides along the arm in such a way that its distance from O is r = 0.9 - 0.12t², where r is expressed in meters and t in seconds. After the arm OA has rotated through 30 degrees, determine the velocity and acceleration of the collar.
A. v = 0.225 m/s, a = -0.24 m/s²
B. v = 0.225 m/s, a = 0.24 m/s²
C. v = 0.45 m/s, a = -0.48 m/s²
D. v = 0.45 m/s, a = 0.48 m/s²