All of the Following Statements Are True EXCEPT

All of the following statements are true EXCEPT:

A) correcting dynamic imbalance can result in the correction of force imbalance at the same time.
B) primary vibrations are only about one-fourth of the strength of secondary vibrations but can become quite severe at the higher rpm at which four-cylinder engines quite often operate.
C) computer balancers compute the combined amount of dynamic and force imbalance and tell where to remove metal to correct them.
D) balance shafts are used to cancel out secondary vibration.