Which three are true about granting object privileges on tables, views, and sequences?

In Oracle Database, object privileges are rights to perform a particular action on a specific object in the database. Here's why the other options are incorrect:

A. UPDATE can be granted on tables, views, and materialized views, but not sequences. B. DELETE cannot be granted on sequences because sequences do not store data that can be deleted. D. INSERT cannot be granted on sequences; sequences are used to generate numbers, not to be inserted into directly. C. REFERENCES allows the grantee to create a foreign key that references the table or the columns of the table. It is applicable only to tables and views. E. SELECT can indeed only be granted on tables and views (including materialized views). F. ALTER is an object privilege that can be granted on tables and sequences but not views.

For more details, one may refer to the Oracle Database SQL Language Reference documentation, which specifies the types of object privileges and the objects they apply to.