Which statement accurately describes a join node?

Which statement accurately describes a join node?

• A. Marks the end of concurrent sequences in an activity
• B. Marks the start of alternative sequences
• C. Represents a lifeline
• D. Is used to model data flow

Answer: (A)

In UML Activity Diagrams, a join node is a synchronization point that merges multiple parallel flows back into a single flow. It waits for all incoming paths to complete before allowing the activity to continue, effectively marking the end of the concurrent sequences. That’s why the statement describing it as the end of concurrent sequences is the best fit. It isn’t about starting alternative paths (that’s a decision/branch concept), it doesn’t represent a lifeline (a sequence diagram element), and it isn’t used to model data flow (that’s handled by other modeling constructs). The join’s job is to synchronize parallel activities and reunite them into one path.

In UML Activity Diagrams, a join node is a synchronization point that merges multiple parallel flows back into a single flow. It waits for all incoming paths to complete before allowing the activity to continue, effectively marking the end of the concurrent sequences.

That’s why the statement describing it as the end of concurrent sequences is the best fit. It isn’t about starting alternative paths (that’s a decision/branch concept), it doesn’t represent a lifeline (a sequence diagram element), and it isn’t used to model data flow (that’s handled by other modeling constructs). The join’s job is to synchronize parallel activities and reunite them into one path.