What is the appropriate unit of measurement for pitch?

There are several definitions of 'pitch', but I think you mean how 'high' or 'low' a sound sounds to our ear.  

If that's it, then you're talking about the frequency of the sound, and the unit is 'vibrations per second' or 'Hertz' (Hz) .

where's the following? you gotta add it to know what the choices are

explanation:

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it