display only the date of births of employees with no duplicates a) select dob from employee union select dob from employ

[answerhappygod]

display only the date of births of employees with no
duplicates
a) select dob from employee union select dob from employee
b) select dob from employee e1 natural join employee e2
c) Select dob From employee Group by dob
none of the above
options a and b are valid
options b and c are valid
options a, b and c are all valid
options a and c are valid