"If you are calling, you have to respond immediately, you can not wait or something. If you send someone a text on Whatsapp, you can think: 'I will respond later.'. When you are calling you do not always have an answer right away, maybe that is the reason why I do not like to call. And you can not call everywhere, when I am at work, I can not call. But I can send a text on Whatsapp, nobody will be disturbed by that and no one can hear it."