Which two methods achieve this?

In theCUSTOMERStable, the values in theCUST_STATEcolumn are dependent on the
values in theCOUNTRY_IDcolumn. You want to make the optimizer aware of this
dependency when these columns are used together inWHEREclause predicates that contain
equalities or in-lists. Which two methods achieve this?(Choose two.)

A.
gathering statistics on theCUSTOMERStable and its dependent objects, and then locking
the statistics

B.
using SQL plan directives to generate an optimal plan

C.
setting the dynamic statistics level to 4 and setting
theOPTIMIZER_USE_PENDING_STATISTICSinitialization parameter to true

D.
creating column group statistics, regatheringstatistics, and ensuring that histograms exist
on both these columns