What does the anther imply by writing the last sentence of the passage

A．Knowing how to operate a motor-car or washing-machine means a high mental intelligence.
B．The technical achievement of Europeans are because of their intelligence.
C．Only knowing how to operate some modem household appliances does not really mean that they are of real intelligence.
D．Europeans are more intelligent than Africans or Asians because they are of mental superiority.