pl/sql function

i have created a function which takes two IN parameters(lets say x and y) of varchar2 type,retturn type is varchar2. this function concatenate two parametes and return the values
which 2 are true
1.this function can be used against any table
2.this function can be used only if two parameters are passed in are not null values
3. this function will generate a sstring based on two character values passed into the function
4. this function can be used only on tables where there is a x and y colum

2,3 are right answers

Option 1 is correct

Options 1 and 3 are correct....

1. yes you can use this function against any table
2. concatenate works with null parameters. So this option is wrong
3. obviously this statement is true
4. No. column names need not have to match with paramter name.

i agree with jamesravid. option 1 and 3 are correct.