Object privileges applicable to tables, views, and sequences in Oracle are:
B . REFERENCES can be granted only on tables. It allows the grantee to create a foreign key that refers to the table.
D . SELECT can be granted on tables and views. This allows the grantee to perform a SELECT on the table or view.
A, C, and E are incorrect. Specifically:
A is incorrect because DELETE cannot be granted on sequences; it is a privilege applicable to tables and views.
C is incorrect because INSERT cannot be granted on sequences; INSERT is applicable only to tables and views.
E is incorrect because ALTER is a privilege applicable to tables and indexes, not sequences.
Reference:
Oracle Database SQL Language Reference, 12c Release 1 (12.1): "GRANT"