How many cookies does Sally want if she is aiming for 3 dozen?

Sally is aiming for 3 dozen cookies. Understanding the term "dozen" is key, as one dozen equals 12 items. Therefore, if Sally wants 3 dozen cookies, the calculation would be:

3 dozen * 12 cookies per dozen = 36 cookies.

This calculation shows that the target number of cookies Sally has in mind is 36, confirming that option C is indeed the correct answer. The other options propose quantities that do not align with the total she is seeking based on the definition of a dozen.