What is the order of placement when creating a route plan?

A.
Route groups are added to gateways and gateways are added to route lists and route lists are added to route pattern.

B.
Gateways are added to route groups and route groups are added to route lists and route lists are added to route patterns.

C.
Gateways are added to route lists and route lists are added to route groups and route groups are added to route patterns.

D.
Route patterns are added to route groups are route groups are added to route lists and route lists are added to gateways.