Examine the code snippet from the declarative section of a PL/SQL block: DECLARE TYPE va1 IS VARRAY(10) OF VARCHAR2(20); SUBTYPE scale IS NUMBER(1,0); TYPE tb1 IS TABLE OF…

Examine the code snippet from the declarative section of a PL/SQL block:

DECLARE TYPE va1 IS VARRAY(10) OF VARCHAR2(20); SUBTYPE scale IS NUMBER(1,0); TYPE tb1 IS TABLE OF departments.department_name%TYPE INDEX BY departments.department_id%TYPE; TYPE tb2 IS TABLE OF va1 INDEX BY PLS_INTEGER; TYPE tb3 IS TABLE OF scale INDEX BY VARCHAR2(10); TYPE tb4 IS TABLE OF DATE INDEX BY DATE; TYPE tb5 IS TABLE OF NUMBER INDEX BY CHAR(2); .... Which of the above are valid definitions for associative arrays? (Choose all that apply.)