Final answer:
To ensure loyalty to Manchu rule, the government mandated all Chinese males to shave their foreheads and wear a queue hairstyle. This served as a loyalty symbol and helped in cultural assimilation. Other measures mentioned like the Gang of Four and Triads are unrelated to the Manchu period's internal control strategies.
Step-by-step explanation:
The Manchu government established certain measures to maintain control and identify those who opposed their rule during their conquest of China. One of these measures was enforcing a new hairstyle called the queue, which involved shaving the forehead and braiding the hair into a pigtail. This was made mandatory for all Chinese males after 1645 under penalty of execution, serving both as a symbol of loyalty to the Manchu rulers and a means of cultural assimilation. Additionally, the Manchu expanded Chinese administrative systems and integrated Chinese officials into their government, as seen during the reign of Hong Taiji after the death of Nurhaci. The Manchu's careful integration of Chinese institutions enabled them to solidify their control over the newly conquered territories.Moreover, during times of resistance, such as the Tai Ping Rebellion and the incursion of foreign powers, the Qing Dynasty faced significant internal strife which they countered with various strategies. However, this questions' focus is on the measures employed by the Manchu government to maintain control domestically.The option regarding the Gang of Four and Triads, mentioned in the choices provided, do not pertain to the Manchu period but are instead related to later historical events and organizations, hence they are incorrect in the context of Manchu measures to maintain control. It's important to note, however, that the Triads did exist at the time as secret societies, some of which were opposed to the Qing Dynasty.