What aspect of behavior does "very strange" refer to?

"Very strange" refers to behavior that deviates from the norm or what is typical in a given context. The term suggests an element of oddness or deviation that distinguishes the behavior from what is usually observed. Therefore, labeling something as "very strange" implies it is uncommon or unusual, which aligns perfectly with the chosen answer.

In contrast, the other options suggest attributes that are incompatible with the notion of strangeness. For instance, "stable" refers to behavior that is consistent and predictable, while "ordinary" denotes behavior that is typical and widely accepted. "Expected" also refers to behavior that aligns with what is anticipated based on established norms. Consequently, these terms do not capture the essence of "very strange," which emphasizes unusualness or rarity.