When troubleshooting an application using AppDynamics, the fastest way to narrow down a code problem with a specific business transaction is to follow this order:

Review Application Dashboard: This is the first step to get an overview of the health and performance of your application and its components. You can see the key metrics, such as response time, throughput, error rate, and load, for each tier, node, and business transaction. You can also see the health rule violations, events, and alerts that indicate any issues or anomalies in your application.

Check transaction scorecard: This is the second step to drill down to the details of a specific business transaction that you want to troubleshoot. You can see the transaction scorecard by clicking on the business transaction name on the application dashboard. The transaction scorecard shows the metrics, such as average response time, calls per minute, errors per minute, and slow calls, for the selected business transaction. You can also see the breakdown of the response time by tier, node, and remote service, and the distribution of the response time by percentile.

Check transaction snapshots for problems: This is the third step to identify the root cause of the code problem for the selected business transaction. You can see the transaction snapshots by clicking on the View Snapshots button on the transaction scorecard. Transaction snapshots are the detailed records of the execution of a business transaction, including the call graph, the exit calls, the errors, the exceptions, the logs, the HTTP parameters, the cookies, the session attributes, and the custom data. You can use the transaction snapshots to analyze the code execution, the database queries, the web service calls, the message queues, the errors, and the exceptions that affect the performance of the business transaction.

Therefore,A(Review Application Dashboard > Check transaction scorecard > Check Transactions snapshots for problems) is the correct answer.Reference:

Cisco AppDynamics Associate Administrator Certification

Troubleshoot Business Transactions - AppDynamics

Business Transaction - AppDynamics

Transaction Snapshots - AppDynamics