Which statement about phaseout dates is correct?

Which statement about phaseout dates is correct?

• A. All CFCs by 1995, R-22 and R-124b by 2010, HFCs by 2035
• B. All CFCs by 1995, R-22 and R-124b by 2020, HFCs by 2030
• C. All CFCs by 1995, R-22 and R-124b by 1990, HFCs by 2025
• D. All CFCs by 1995, R-22 and R-124b by 2025, HFCs by 2030

Answer: (B)

Phaseout dates show how regulations gradually eliminate ozone‑depleting substances and move toward safer alternatives. All CFCs were phased out by 1995 because they cause the most ozone depletion, a milestone set by international and U.S. regulations. R‑22 and R‑124b are HCFCs, which also harm the ozone but to a lesser extent, so their phaseout is scheduled later—commonly around 2020 in many regulatory timelines. HFCs do not deplete the ozone, so they are addressed later to curb their high greenhouse gas impact, with dates often around 2030. This combination—CFCs by 1995, HCFCs by about 2020, and HFCs by about 2030—best matches established schedules, while earlier dates for HCFCs or delays for CFCs would not align with how these regulations were implemented.

Phaseout dates show how regulations gradually eliminate ozone‑depleting substances and move toward safer alternatives. All CFCs were phased out by 1995 because they cause the most ozone depletion, a milestone set by international and U.S. regulations. R‑22 and R‑124b are HCFCs, which also harm the ozone but to a lesser extent, so their phaseout is scheduled later—commonly around 2020 in many regulatory timelines. HFCs do not deplete the ozone, so they are addressed later to curb their high greenhouse gas impact, with dates often around 2030. This combination—CFCs by 1995, HCFCs by about 2020, and HFCs by about 2030—best matches established schedules, while earlier dates for HCFCs or delays for CFCs would not align with how these regulations were implemented.