In a data-flow diagram (DFD), an open-ended rectangle (open rectangle) symbolizes which element?

Introduction / Context:
Data-flow diagrams use a small set of symbols to describe how data move and are stored. The open-ended rectangle (often drawn as two parallel lines or an open rectangle) denotes a data store, i.e., data at rest that can be read or written by processes.

Given Data / Assumptions:

• Notation follows common DFD styles (e.g., Yourdon, Gane–Sarson).
• External entities are squares/rectangles; processes are circles or rounded rectangles; flows are arrows; stores are open rectangles/parallel lines.
• We are identifying the symbol “open rectangle”.

Concept / Approach:
The open-ended rectangle indicates persistence. Processes exchange data with stores via flows. Unlike external entities (outside the system boundary), stores are internal repositories—files, tables, or queues—that hold data between process executions.

Step-by-Step Solution:
1) Map each DFD element to its standard symbol. 2) Recognize that the open rectangle corresponds to a store, not a process or external entity. 3) Confirm that arrows represent flows; circles represent processes; squares represent external entities. 4) Select the option describing a data store.

Verification / Alternative check:
Symbol tables in systems analysis references consistently show open rectangles (or parallel lines) for data stores.

Why Other Options Are Wrong:
Option A: External entities are closed squares/rectangles, not open-ended.
Option B: Flows are arrows.
Option C: Processes are circles/rounded rectangles.
Option E: Not applicable because the correct symbol meaning is present.

Common Pitfalls:
Confusing external entities with stores; remember that stores imply persistence inside the system boundary.

Final Answer:
A data store—data at rest or a temporary repository