Which of the following refrigerant conversions is not considered a drop-in?

Which of the following refrigerant conversions is not considered a drop-in?
 
  A) HFC-134a for HCFC-22
  B) HCFC-409A for CFC-12
  C) HFC-407C for HCFC-22
  D) HCFC-123 for CFC-11

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[Ques. 2] Which currently available refrigerant can no longer be installed in new equipment at the manufacturing level?
 
  A) HFC-134a
  B) HCFC-22
  C) HFC-410A
  D) HFC-407C

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[Ques. 3] Which of the following statements about converting a system from one refrigerant to another is incorrect ?
 
  A) Synthetic and mineral oils are completely compatible.
  B) A new metering device may be required.
  C) Equipment capacity may change with the new refrigerant.
  D) Gaskets and O-rings may have to be changed.

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[Ques. 4] If oil is not returning to the compressor, a possible cause is _____.
 
  A) poorly designed refrigerant piping
  B) oil viscosity
  C) incorrect refrigerant type
  D) that the oil is too miscible

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[Ques. 5] The _____ resolves conflicts between drawings and specifications.
 
  A) architect/engineer
  B) project manager
  C) owners construction manager
  D) owners design-build contractor