To answer this question, you need to understand the concept of level numbers in COBOL.
In COBOL, a level number is used to define the structure and hierarchy of data items within a record or data structure. It indicates the nesting level of the data item.
Let's go through each option to understand which level numbers can be used to describe a record:
Option A) 01 to 49 (both inclusive) and 77 - This option is incorrect. While level numbers 01 to 49 can be used to define data items within a record, level number 77 is used to define a special type of data item called a "condition name". It is not used to describe the structure of a record.
Option B) 01 to 49 (both inclusive) - This option is correct. Level numbers 01 to 49 can be used to define data items within a COBOL record. These level numbers represent the hierarchy of the data items, with level 01 being the highest level and level 49 being the lowest level.
Option C) All odd numbers from 01 to 49 - This option is incorrect. While level numbers 01 to 49 can be used to define data items within a record, there is no requirement or convention to use only odd numbers for defining levels.
Option D) All even numbers from 01 to 49 - This option is incorrect. While level numbers 01 to 49 can be used to define data items within a record, there is no requirement or convention to use only even numbers for defining levels.
The correct answer is option B) 01 to 49 (both inclusive). This option is correct because level numbers 01 to 49 can be used to describe the structure and hierarchy of data items within a COBOL record.