Answer the following question given this paragraph: 

the current. Capacitors can be used to filter out low frequencies. For example, a capacitor in series with a sound reproduction system rids it of the 60 Hz hum.


Q: Capacitors can be used to filter out low frequencies. for example, a capacitor in series with a sound reproduction system rids it of the 60 hz what?

 Choices:

- white noise

- vibration

- echo

- hum

A:
hum
