Which two are true about Oracle Optimizer Statistics, their use, and their collection?

The number of table rows is considered when evaluating the cost of accessing a table using an index.

Index balanced B*Tree height is considered when evaluating the cost of using an index.

The Statistics Advisor can help recommend the best way to gather statistics.

Statistics collected using DBMS_STATS always yield the best optimizer result.

The Statistics Advisor generates actions for all recommendations.