Which shape in a flow diagram denotes a data store?

The shape that denotes a data store in a flow diagram is represented by two parallel horizontal lines. This symbol is used to signify a place where data is stored, which allows flow diagrams to illustrate where information resides within a system or process.

In context, each of the other options serves different functions. For instance, a solid line with an arrow typically indicates the flow of control or data through the system, representing the direction of movement from one process or component to another. A dashed line might represent a relationship or a connection that is less direct or indicative of optional pathways within the process. A rectangle usually signifies a process or function within the flow diagram, denoting actions taken or functions performed rather than storage of data.

Understanding these symbols is vital for accurately analyzing and designing effective flow diagrams. Thus, recognizing the correct symbol for a data store is critical in the context of secure software design, where data management and storage play a pivotal role.