Height of the tree

An advantage of working with a clustering method like hierarchical clustering is that you can describe the relationships between your observations based on both the distance metric and the linkage metric selected (the combination of which defines the height of the tree).

Based on the code below what can you concretely say about the height of a branch in the resulting dendrogram?

dist_players <- dist(lineup, method = 'euclidean')
hc_players <- hclust(dist_players, method = 'single')
plot(hc_players)

All of the observations linked by this branch must have: