______ is meant that a conversational implicature is attached to the semantic content of what is said, not to the linguistic form.

A．Because the CFCs directly damage the people’s health.
B．Because the CFCs are poisonous chemicals.
C．Because the production of the CFCs costs a lot.
D．Because the CFCs can attack ozone by liberating atoms of chlorine.

A．that CFC manufacture is completely forbidden
B．that the production of CFC is reduced
C．to find substitutes for CFCs
D．to reduce the danger of CFCs