A data engineer noticed improved performance after upgrading from Spark 3.

Adaptive Query Execution (AQE) is a Spark 3.x feature that dynamically optimizes query plans at runtime. One of its core features is:

Dynamically switching join strategies (e.g., from sort-merge to broadcast) based on runtime statistics.

Other AQE capabilities include:

Coalescing shuffle partitions

Skew join handling

Option A is correct.

Option B refers to statistics collection, which is not AQE's primary function.

Option C is too broad and not AQE-specific.

Option D refers to Delta Lake optimizations, unrelated to AQE.

Final Answer: A