Very good, lastochka.
From the sum 104 compare to 3*30=90 we can conclude that there must be a lot of 3s. The larger the other numbers are, the more 3s we can have; the smaller the other numbers are, the less 3s we can have.
So we can assume the other numbers are 4.
In other words, we will have at least 16 3s. And therfore the median of these 30 numbers would 3.
Therefore (B) is the answer.
Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.