[单选题]
A wheel starts from 3nb7cl3qx 9eb.y6f ted+i7 afresw 9xcff21h5t dt and reaches an angular speed of 6.0 rad/s while turning through 2.0 revolutions. Whafthcxf2 51w9d t is the average angular acceleration of the wheel?
A. $0.24 \; rad/s^2$
B. $1.4 \; rad/s^2$
C. $3.0 \; rad/s^2$
D. $9.0 \; rad/s^2$
