The performances in relation to Whorf's claim of the Dani and the Piraha are______.

A．experts' different understandings of intention of the attack
B．the difficulty to find out the gangs behind this act
C．people's doubt about winning the lawsuit against SCO
D．the problem with the security of information management

A．a newspaper magazine
B．a technician's report
C．a college textbook
D．a science thesis