Using a Data dictionary

As an ABAP Developer, which of these statements related to data dictionary in SAP ABAP would you consider to be true?

Options

1. Data Dictionary holds object information of programs and classes.
2. All SAP related metadata is stored in TCODE SE11 where the information of a table, data element, domain and views can be taken.
3. Enhancements related data objects are stored in the data dictionary
4. None of these