Question 51: Which statements about the queries below are correct?

1. select now(),database() from dual;
2. select now(),database();

 
(Select all correct answers)
 
a) Query 2 is invalid.
b) Query 1 is valid only, if a table called dual exists.
c) Query 1 and 2 are valid and do exactly the same.
d) Dual is a dummy table-reference and acts like a table with 1 row.