Eric, a professional hacker, is trying to perform a SQL injection attack on the back$-$end database system of the InfomationSEC, Inc. During the information gathering process, he identifies that MYSQL server is the back$-$end database engine used. Eric has tried various SQL injection attack attempts based on the information gathered but all of his attempts failed. Later, he discovered that IPS system is blocking all the SQL injection attack attempts. Eric decided to bypass the IPS using string concatenation IPS evasion technique where he needs to break the SQL query into a number of small pieces and concatenates the SQL query end$-$to$-$end.

Which of the following string concatenation operator Eric need to use in the SQL query to concatenate the SQL query end$-$to$-$end?

A$.$

$||$ operator

B$.$

$$concat$(,)$ operator

C$.$

$+$ operator

D$.$

$$&$$ operator