In determining pitch, what is meant by frequency?

In determining pitch, the frequency is the unit used to measure the pitch. Pitch can be determined in sounds which have a frequency that is clear and stable enough to distinguish from other background noise. The pitch of complex tones can be ambiguous, meaning that two or more different pitches can be perceived, depending upon the listener.

Es la plaza españa de colombia creo

The answer is a if martyn did it without owner's permission.: )