Step 1: Children vs. [r].
Across Regions 1–3, children use [r] at only 2\%, 2\%, and 0\% respectively, overwhelmingly choosing [j] or [É].
\(\Rightarrow\) (A) True.
Step 2: Adult trend in [r] by region.
Adults' [l] usage falls 88\% → 27\% → 1\% from Region 1 to 2 to 3, showing a clear progressive loss (dialect shift).
\(\Rightarrow\) (B) True.
Step 3: Children's preferred variant and divergence from adults.
Children favor [j] most in all regions (75\%, 80\%, 78\%). Adult dominants are different: R1 \([l]\), R2 \([l]\), R3 \([l]\). Thus children diverge from adult patterns and choose [j] preferentially.
\(\Rightarrow\) (C) True.
Step 4: Correlation with adult dominant variant.
Since children pick [j] in all regions while adults' dominant choice varies (\([r]\) or \([l]\)), there is no direct correlation.
\(\Rightarrow\) (D) False.
\[
\boxed{Correct Answer: (A), (B), (C)}
\]