According to 33 CFR §164.35, the turning circle diagram required on the wheelhouse maneuvering fact sheet must show the advance and transfer for a course alteration of how many degrees?

Why C is correct

33 CFR §164.35(g)(1) requires the turning circle diagram to show the time and distance, advance and transfer required to alter course 90 degrees with maximum rudder angle and constant power settings. No other alteration angle is specified for this required diagram.