The correct answer is option 2: China. Weibo is a social media platform that is primarily used in China. It is often referred to as the "Chinese Twitter" because of its similarities in terms of features and functionalities. Weibo allows users to post short messages, photos, and videos, as well as follow other users and interact with their content through likes, comments, and shares. It has a significant user base in China and is widely used by individuals, businesses, and celebrities to share updates and engage with their audience. While social media platforms like Weibo may be popular in other countries as well, such as South Korea, Thailand, and Japan, the dominant usage and popularity of Weibo is in China.