The correct answer is C: Keying speed and shape factor (rise and fall time). The factors that affect the bandwidth of a transmitted CW signal are keying speed (how fast you're sending) and shape factor (the rise and fall time of the keying waveform). These determine how fast the signal transitions and thus the bandwidth. Faster keying speed means shorter dots and dashes, creating more rapid transitions and wider bandwidth. Slower rise/fall times (gentler transitions) create narrower bandwidth, while faster rise/fall times (sharper transitions) create wider bandwidth. The shape factor (rise and fall time) is particularly important - very short rise/fall times create key clicks (wide bandwidth), while longer rise/fall times keep bandwidth narrow. IF bandwidth and Q affect receiver performance but don't directly affect transmitted signal bandwidth.