9A46 A
 On Figure 9A-2, in troubleshooting a PLL, you find that the signals f1 and f2 are the same frequency but are 45 degrees out of phase.
A. This is normal.
B. Check the Low pass filter for correct cutoff frequency.
C. The VCO is low in gain.
D. The input signal is slewing faster than the VCO can follow.
