Concept: AACR-2 main entry contains different sections for identifying and describing a document.
Step 1: Check ISBN.
ISBN is a standard section used for identifying the book.
\[
D = \text{Section of main entry}
\]
Step 2: Check Note.
Note section gives extra descriptive information about the book.
\[
A = \text{Section of main entry}
\]
Step 3: Check Tracing.
Tracing shows the added entries and references made in the catalogue.
\[
B = \text{Section of main entry}
\]
Step 4: Reject Common Communication.
Common Communication is not a section of AACR-2 main entry.
Therefore, the correct set is:
\[
D,\ A,\ B
\]