In a subtractive synth, which circuit determines the initial pitch?

The correct answer is D. Voltage Controlled Oscillator (VCO).

The Voltage Controlled Oscillator is responsible for generating audio signals at specific frequencies, which determines the initial pitch in a subtractive synthesizer. It converts voltage control signals into audio waveforms, allowing the user to control the pitch based on the input voltage. If you have any more questions or need further explanations, feel free to ask!