How do decision support systems $($DSS$)$ and executive information systems $($EIS$)$ generally differ in their use of data and support for decision$-$making types?

Select one:

a$.$ Decision support systems are typically built to use external data sources, whereas executive information systems rely on internal data for decision support.

b$.$ Decision support systems exclusively rely on internal data and do not incorporate external sources.

c$.$ Executive information systems solely utilize internal data to aid in structured decision$-$making.

d$.$ An executive information system is designed to use data from external sources to aid in unstructured decision$-$making, while a decision support system generally uses internal data sources to assist with semi$-$structured decisions.