What GoldenGate process is responsible for capturing changes in the source database?

What GoldenGate process is responsible for capturing changes in the source database?

A.
Manager

B.
Replicate

C.
Extract

D.
Server Collector

Explanation:

Reference:
http://download.oracle.com/docs/cd/E15881_01/doc.104/gg_wux_ref_v104.pdf