When setting up a search, what are the things to keep in mind?

When setting up a search, what are the things to keep in mind?
A . Enterprise Search must be installed, either in embedded form or as the central search engine, to use MDG for Material.
B . As of MDG 7.0 SP2 Feature Pack, you can use SAP HANA-based search to connect the MDG database to an SAP HANA-based system for search.
C . The data model and entity type can be selected directly (this can also be preset by customizing or configuration).
D . For edition-based data, validity time can be used as search criteria, and is displayed in the result list.

Answer: A,B