Henriette, see mizinamo's comment. We are drilling relative pronouns here, not interrogatives. The primary meaning of 'ami' is 'that' or 'which',and it can sometimes mean "that which".
In English, 'what' can sometimes be substituted for 'that which'. For example, 'She gives me what I need' = 'She gives me that which I need'. But this substitution is for 'that which', not for 'that'.
In any case, note that the DL phrase here is a fragment, not a complete sentence.
Although the exercise will fail you for giving the most faithful translation, please be aware that the real meaning is "that which" the A prefix always operates like this . That which, he who etc.. As the Honourable ion1122 has said these are not Interrogatives. Enjoy your studying and try not to lose your Goddam minds tesók.
Ray, we don't have anything in the Hungarian phrase that translates as "that". (Saying this as the given translation literally says "that". English is complicated.)
The Hungarian phrase is a single relative clause which is used to describe something, but we don't mention the thing that is described at all.
"That which is outside, not inside" would be "Az, ami kint van, nem bent."