You need to ensure that all the execution trees run in parallel

You are performance tuning a SQL Server Integration Services (SSIS) package to load sales
data from a source system into a data warehouse that is hosted on Windows Azure SQL
Database. The package contains a data flow task that has 10 source-to-destination
execution trees.
Only five of the source-to-destination execution trees are running in parallel.
You need to ensure that all the execution trees run in parallel.
What should you do?

A.
Add OnError and OnWarning event handlers.

B.
Create a new project and add the package to the project.

C.
Query the ExecutionLog table.

D.
Add an Execute SQL task to the event handlers.