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 seven source-to-destination execution trees.
Only three 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.
Set the EngineThreads property of the data flow task to 7.

B.
Set the MaxConcurrentExcecutables property of the package to 7.

C.
Create seven data flow tasks that contain one source-to-destination execution tree each.

D.
Place the data flow task in a For Loop container that is configured to execute seven
times.