The opposite of word "MAY" is "NEVER". If we consider the first statement of copper smelting wrong...then we are technically saying that ..copper smelting unit will never release the legal quality of CO..be whatsoever. It will be very unlikely scenario considering the complex process which takes place in melting.
In the virus question ...we all are missing one important key word..which is artificial. PYQ was dealing with only synthetic medium...this time we have one additional word in the question which is artificial.
Cell culture of virus in laboratory under controlled conditions is culture of virus in artificial medium .