Deductions & credits

Just read this:

New Jersey: In New Jersey, renters have two choices when it comes to the renter's tax credit. The first is to take a deduction on their taxes of 18% of the amount paid in rent, while the second is a flat $50 credit on their taxes.

 

so based on my son  paid 5804 then why isnt turbotax doing 18% deduction of $1044 instead doing credit of $50