Statement — A UN report reviewing the ozone layer since the Montreal Protocol (1987) reveals that the ozone hole over Antarctica is shrinking. Question — Which conclusion necessarily follows from the statement?

Introduction / Context:The stem states an observed environmental trend: the Antarctic ozone hole is shrinking. Two conclusions are offered about chlorofluorocarbons (CFCs): (I) removal now exceeds new releases; (II) atmospheric levels of destructive CFCs are declining. We must identify the inference supported by the report without adding stronger claims.

Given Data / Assumptions:

• Ozone hole size is decreasing.
• Context references the Montreal Protocol aimed at reducing CFCs.

Concept / Approach:A shrinking hole is consistent with falling concentrations of ozone-depleting substances (ODS) like CFCs. However, claiming that natural/atmospheric removal outpaces total releases (I) is a stronger, quantitative dynamic not stated in the stem.

Step-by-Step Solution:

Verification / Alternative check:The hole could shrink due to lower emissions plus slow stratospheric cleansing; we are not told the current balance is removal > release in all regions/times. Thus II, not I, follows.

Why Other Options Are Wrong:

Common Pitfalls:Conflating “improving indicator” with a specific quantitative mechanistic claim.

Final Answer:if only conclusion II follows