The correct answer is B.
The Tiananmmen Square protests took place in 1889 in Beijing (Chinese capital), and they were mainly headed by students who protested against the Communist goverment and who claimed for the establishment of basic human rights and press rights.
The protests were violently repressed by the Chinese army after martial law was declared. The troops used assault rifles and tanks to shoot the demonstrators. More than 10,000 civilians ended up killed.
After this event, Chinese leaders implemented an even more rigid system aiming to erradicate potential democratic desires.