Cultural lag refers to the gap when the changes in material culture are followed with a certain delay by spiritual culture (law, custom, tradition, social mentality, etc.) Especially the changes in the technology dimension of material culture enable the cultural lag to be seen strikingly. Thus it is an example of cultural lag when people who did not own mobile phones until recently talk on the phone in a way that annoys people in their surroundings after receiving a mobile phone. The correct answer is A.