To solve this question, the user needs to know about bitwise operators. The bitwise operators manipulate the bits of binary numbers. The operator that converts 00110011 into 11001100 is the NOT (~) operator.

The NOT (~) operator inverts the bits of a binary number. Applying the NOT operator to 00110011 will result in 11001100.

Now let's go through each option and explain why it is right or wrong:

A. ~: This option is correct. The NOT (~) operator inverts the bits of a binary number. Applying the NOT operator to 00110011 will result in 11001100.

B. !: This option is incorrect. The exclamation mark (!) is not a bitwise operator. It is a logical operator used for negation in programming languages.

C. &: This option is incorrect. The AND (&) operator performs a logical AND operation between two binary numbers, which results in a binary number that has a 1 in each bit position where the corresponding bits of both operands are 1. It does not convert a binary number to another form.

D. |: This option is incorrect. The OR (|) operator performs a logical OR operation between two binary numbers, which results in a binary number that has a 1 in each bit position where at least one of the corresponding bits of either operand is 1. It does not convert a binary number to another form.

The Answer is: A