Which is NOT discussed as a major aspect of "culture"

A．A chimpanzee can learn to use sign language to make sentences.
B．Other animals can invent tools.
C．Sharing and cooperating are no longer signs of only human behaviour.
D．The line dividing human culture from animal culture is not as clear as we might think.

A．people can only find jobs in catering business
B．high-tech employees are not as highly regarded as before by many companies
C．skilled employed workers are eager to take another job once it is available
D．a company will adjust the pay according to its employees' experience rather than their education