What is variable-length structure called?

In which database table type is there a one-to-one relationship between the Dictionary table definition and the relevant physical table in the database?
Please choose the correct answer.
Response:

An internal table line type with a deep or nested structure can be defined for internal tables with a header line.

How to call the stored procedures in ABAP code?
Please choose the correct answer.

An internal table can have primary keys as well as secondary keys.