The correct answer is: A. a secondary access path.
An embedded pointer is a pointer that is stored within a data record. It can be used to provide a secondary access path to the data record, which can improve the performance of queries that need to access the data record based on the value of the pointer.
A physical record key is a unique identifier for a data record. It is stored in the data record itself, and it is used to locate the data record on disk.
An inverted index is a data structure that is used to improve the performance of queries that need to access multiple data records that have the same value for a particular field. It is not a secondary access path, because it does not provide a direct way to access the data records.
Therefore, the correct answer is A.