What must be done, at a minimum, before a system can legally be opened up for repairs while adhering to the prohibition against the venting of halogenated fluoro-carbon refrigerants to the atmosphere?

Correct Answer: Option D — recovery of the refrigerant

EPA and marine environmental regulations mandate that halogenated fluorocarbon refrigerants must be captured prior to opening any system. Recovery ensures ozone layer protection and complies with strict federal standards.