Where are GoldenGate macros defined?

A.
Macros can be defined in the parameter file or included in a macro file

B.
Macros are defined in the GLOBALS parameter file

C.
Macros are placed in a file and referenced using an environment variable.

D.
Macros are declared, compiled and referenced via Golden Gate’s user exits.

Explanation:
Reference:
http://download.oracle.com/docs/cd/E15881_01/doc.104/gg_nsk_admin_v10.pdf