How are contexts defined?

How are contexts defined?
A . They are automatically defined by the types of components used in the Job.
B . Talend Studio defines a default context, and you can define more as needed.
C . You must define the contexts
D . In addition to a default context, Talend Studio defines a list of standard contexts you can use in your Ions.

Answer: C

Explanation:

Contexts are a way of defining different sets of values for variables that are used in a job. For example, you can define a context for testing and another context for production, with different values for the database connection parameters, file paths, etc. You can then switch between the contexts easily without modifying the job design. Contexts are not automatically defined by the types of components used in the job, nor by Talend Studio. You must define the contexts yourself in the Contexts tab of your job. You can also create context groups in the Repository and reuse them in multiple jobs.

Reference: Talend Data Integration ― Software to Connect, Access, and Transform Data | Talend,