C. There are three main advantages to having mobile phone. Firstly, there is the convenience of being able to make or receive a phone call at any time and in any place. Secondly, they are essential for keeping in touch with family and friends. Parents worried about their children can always ring them to check they are safe, and children can let their family know if they are going to be late home. Finally, mobile phones can save lives. For example, if there is an accident, help can be called immediately, where the accident takes place.