When dealing with subgroups for Continuous Data and outliers, Xbar-R charts are more appropriate. Xbar-R Charts are used for smaller subgroup sizes (typically n ≤ 10). They help monitor the variation within subgroups and the variability between subgroup averages, which is suitable when subgroups are present. While both Xbar-R and Xbar-S charts deal with subgroups, Xbar-S charts are preferred for larger subgroup sizes (n > 10), making Xbar-R the correct choice for smaller subgroups.