While Having a Discussion, Technician a Says That to Extend

While having a discussion, Technician A says that to extend U-joint service life, the angle of the transmission output shaft and the front of the differential should be within 2 degrees of each other. Technician B says that the differential should be within 1/2 degree of each other. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B