How do you control which attributes are exposed to the transformers in a custom transformer or output from the custom transformer?

How do you control which attributes are exposed to the transformers in a custom transformer or output from the custom transformer?

• A. Double-click on the Transformer Input or Transformer Output port and check/uncheck the attributes
• B. Navigator > Transformer Parameters > Group By
• C. Tools > FME Options
• D. Use an AttributeExposer before the custom transformer input and output port(s)

Answer: (A)