Answer - A and D.
The AWS Documentation mentions the following.
Many applications can benefit from using parallel Scan operations rather than sequential scans.
For example, an application that processes a large table of historical data can perform a parallel scan much faster than a sequential one.
Multiple worker threads in a background "sweeper" process could scan a table at a low priority without affecting production traffic.
In each of these examples, a parallel Scan is used in such a way that it does not starve other applications of provisioned throughput resources.
If possible, you should avoid using a Scan operation on a large table or index with a filter that removes many results.
Also, as a table or index grows, the Scan operation slows.
The Scan operation examines every item for the requested values and can use up the provisioned throughput for a large table or index in a single operation.
For faster response times, design your tables and indexes so that your applications can use Query instead of Scan.
Option B is incorrect since having larger tables would make the issue worse.
Option C is incorrect since this would not help in the issue.
