In DynamoDB, a secondary index is a data structure that contains a subset of attributes from a table, along with an
alternate key to support ____ operations.

A.
None of the above

B.
Both

C.
Query

D.
Scan

Explanation:
In DynamoDB, a secondary index is a data structure that contains a subset of attributes from a table, along with an
alternate key to support Query operations.
http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/SecondaryIndexes.html