"Kateřina wants to have three children."
Translation:Kateřina chce mít tři děti.
I think a lot of people are being confused by the fact you entered the same option twice.
I looked at the question and had 1 and 3 the same - if you are posting the same phrase twice on the multiple choice + having mark all correct meanings it can be confusing at first.
I take it back. It's that damned í !!! Apologies for misreporting this as erroneous.
There was twice the exact same correct sentence as choice: "Kateřina chce mít tři děti". I selected both of them and it was marked as wrong.
Error in the form, Katerina chce tři děti appeared twice. I chose the wrong one.