Which transitional expression is related to timing?

The transitional expression "afterward" is directly related to timing because it indicates a sequence of events that occur following a specific point in time. This word helps the reader understand the chronological order of actions, suggesting what comes next after certain events have taken place.

In contrast, other options like "in addition" generally connect ideas or add information without a focus on timing, while "meanwhile" suggests simultaneous actions rather than a sequential order. "For example" serves to introduce illustrations or instances rather than indicating when something happens. Thus, "afterward" is the most appropriate choice as it clearly conveys a relationship involving timing and sequence.