Why does US Congress launch federal investigation against Tik Tok?
A.
They fear that TikTok may force Facebook and other social media out of business.
B.
They fear that TikTok may have illegal data-collecting and censorship by foreign government and may interfere US internal affairs.
C.
They fear that TikTok is controlled by several US senator to cheat in US election.
D.
They fear that TikTok may be used by Russian government to interfere US election.