Answer: Ancho de banda
Explanation: We need to see the relevant feature when choosing an internet service provider:
The options are:
Ancho de banda (Wavelenght, directly related to the speed of the service)
Cámara web (Webcam)
Micrófono (Microphone)
Parlantes (Speakers)
The only option related to the internet service is the first one, so the answer is "Ancho de banda"