Which statement accurately describes a fork node?

• A. Marks the start of concurrent sequences in an activity
• B. Marks the end of alternative sequences
• C. Represents a lifeline
• D. Is the notation for a decision node

Answer: (A)

A fork node signals parallelism in an activity diagram. It takes one incoming flow and splits it into multiple concurrent outgoing flows, marking the start of concurrent sequences that run at the same time. This is why the statement describing it as the start of concurrent sequences is correct. It’s not about ending alternative paths (that’s a join/merge concept), not a lifeline (that’s from sequence diagrams), and not a decision node (that’s a branching point based on conditions). So the fork’s role is to initiate parallel, concurrent branches in the workflow.