Which two statements are true about gathering statistics?

Which two statements are true about gathering statistics? (Choose two.)

A.
If an application has only SQL statements with bind variables, it is better to drop existing
histograms, disable creation of histograms, and allow the optimizer to select the best
execution plans.

B.
If end users query newly inserted data, it is possible to get a suboptimal execution plan
even if the automatic statistics gathering job is enabled.

C.
If concurrent statistics gathering is done by using parallel execution, the Resource
Manager should be used for efficient resource management.

D.
For each session that is accessing a global temporary table, the optimizer uses only the
shared statistics.